Re: NIST SRM656 Analysis

[iangie]

Dear Matthew,


I scanned our SRM α 656 using CoKα Dynamic Beam Optimation machine from 2 to 
150 °2θ. 
https://www.dropbox.com/s/rar6sjepl9g2x2d/ROW.pro?dl=0 
Using the same sample model, the derived relative wt% ratio between α and β 
phases are very similar to that from your CuKα data.




Cheers!

--

Dr. Xiaodong (Tony) Wang
Senior Research Infrastructure Specialist (XRD)
Central Analytical Research Facility (CARF)   |  Queensland University of 
Technology
Address: Level 6, P Block, Gardens Point campus, 2 George St Brisbane QLD 4000
Tel: +61 7 3138 1904  |   Mob: 0452 571 680
Email:   tony.w...@qut.edu.au   |   Web: www.qut.edu.au/ife/carf




在 2022-04-30 11:53:46，"Matthew Rowles"  写道：

Hi Tony


I can't reproduce the certificate values. This is the entire point of my 
question. 


Matthew


On Fri, 29 Apr 2022, 08:31 iangie,  wrote:

Dear Mathew,


Understood these values are from the SRM certificate.
My .pro of the data suggests ~92% alpha, 3% beta, and ~5% Amorphous:
https://www.dropbox.com/s/r2l4y0iq7d4baj7/ROW.pro?dl=0
Can you reproduce those values on the certificate?


Cheers!

--

Dr. Xiaodong (Tony) Wang
Senior Research Infrastructure Specialist (XRD)
Central Analytical Research Facility (CARF)   |  Queensland University of 
Technology
Address: Level 6, P Block, Gardens Point campus, 2 George St Brisbane QLD 4000
Tel: +61 7 3138 1904  |   Mob: 0452 571 680
Email:   tony.w...@qut.edu.au   |   Web: www.qut.edu.au/ife/carf




在 2022-04-27 15:55:28，"Matthew Rowles"  写道：

Yep.


The sample is supposed to contain 87.4 wt% alpha-Si3N4, 3.0 wt% beta-Si3N4 and 
9.6 wt% amorphous.


Matthew


On Tue, 26 Apr 2022 at 20:06, Martin Vickers  wrote:

Just a point of interest you seem to have a few impurity peaks possibly from 
Si6N8 (COD entry 96-210-2554 seems to match well). it's not a lot but  you 
might want to include that phase in your quantitative calculations.


Regards,


Martin




--

Martin Vickers
Dept. of Chemistry, UCL,
20, Gordon Street
WC1H 0AJ
020 7679 5592 (or ex 25592)
++
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RE: NIST SRM656 Analysis

[Elena Lounejeva]

Good day everybody,

I agree with Holger. I'd be happy to help organise a RR for amorphous content 
quantification if somebody takes over. Count me in.

Hi Matthew,

I came back to your question after your last message on April 30th. I only know 
how to estimate amorphous using the internal calibration in Topas; therefore, I 
made an approximate estimation. I summed both of your XY files below and put 
them into the attached .pro file. Doing that, I have noticed a couple of 
things. First, I have noticed that the Bg is a bit convex, and you probably 
would like to double-check your instrumental setup (was it the silicon holder? 
0.5 or 3 mm air screen? A narrow incident slit? Or something else). Second, 
please review the instrumental parameters in the attached *.pro file as I use 
D2 and am not familiar with D8 details. Third, I'm not sure how to improve 
refinement for Corundum, but it is definitively deficient, as you can see on 
the residual curve and high Rwp ~7.
I firstly ran refinement of the mixture with three structures and got ~55% of 
Corundum which is logical given the uncertainty introduced by summing the BGs. 
Then I fixed it as an internal standard at 55%, and obviously, Amorphous 
content was very low (try and see the result). So I tried several values down 
to 50% for Corundum and got the best match for Corundum ~52.5% with Rwp~6:


Phase
Wt% in mixture
Wt% in original
Cor
52.5

Alpha
41.47
87
Beta
1.16
2.5
Amor.
4.87
10

You probably can improve it. 
https://www.dropbox.com/s/r0stzrl8so0h43x/ROW.pro?dl=0
A proper calculation should be much better after running a physical mixture 
with ~10-20 wt% of Corundum by weight rather than simply summing the data and 
using each simple structure refined for the instrument setup (I agree to DO NOT 
refine Beq) before refining the mixture. I'd be relatively happy with the 
result, but the problem remains with the "unknown" samples…

Please review and share your thoughts. Bets wishes,
Elena

PS

"Why I'm getting negative amorphous in Topas using IS internal method?" - is 
the most off-putting question from our students. In DIFFRAC.EVA, any powder 
will show some %-Amorphous if we compute crystallinity using the Default Bg 
model parameters  (Curvature=1,  Threshold=1 and No Enhancement). However, even 
if the powder is known to have an amorphous phase, the %-Amorphous would be =0% 
if we use a flat Bg with curvature=0. In Topas, the "Amor" accounts for the 
difference between what is identified,  refined and weighted relative to 
internal standard; thus, Amor includes all the unknown phases, either amorphous 
or not-identified crystalline) and it is also Bg and many other things 
-sensitive. My understanding of the matter so far: refinement is instrument 
sensitive; therefore, it is essential to run reference materials and calibrate 
each instrumental setup for the purposes, model background or amorphous and 
save it as a scan, load in Topas, model it as an hkl phase, estimate 
proportions as semi-quant for the known SRM and only if a general refinement 
gives a reasonable amount (+-1%?) we could use it with the internal std. Also, 
the external method should give better results when you have a mixture of 
well-known references in several proportions, a kind of calibration curve. This 
is what Matt is going through, although this approach is time-consuming.

From: rietveld_l-requ...@ill.fr<mailto:rietveld_l-requ...@ill.fr> 
mailto:rietveld_l-requ...@ill.fr>> On Behalf Of 
Matthew Rowles
Sent: Tuesday, 19 April 2022, 4:20 PM
To: Holger Kletti 
mailto:holger.kle...@uni-weimar.de>>
Cc: RIETVELD_L Distribution List mailto:rietveld_l@ill.fr>>
Subject: Re: NIST SRM656 Analysis

Hi Holger

There is a good paper by Ian Madsen, Nikki Scarlett, and Arnt Kern about the 
quantification of amorphous materials - 
https://doi.org/10.1524/zkri.2011.1437<https://doi.org/10.1524/zkri.2011.1437>

On the RR, I'll let the CPD know!

Matthew

On Thu, 14 Apr 2022 at 16:51, Holger Kletti 
mailto:holger.kle...@uni-weimar.de>> wrote:

an actual RR on amourphous contents like thos on crystalline mixtureswould 
really be appriciable, i don't know any publications therewith. The problem 
seems to exist as can be seen here, but also with internal standard method, as 
in personal discussions the question on achieved negative amorphous contents 
(internal as well as external standard method) arises from time to time. And 
not alway this can be solved just by variation of background polynoms or other 
structure related parameters.

So if "anyone" would initiate such a RR i would like to join it 

Holger
Am 14.04.2022 um 09:49 schrieb Julian Richard Tolchard:
I confess that this discussion seems to validate my personal choice to treat 
Rietveld quantification (and especially amorphous quant) as something lying 
between a quantificational and semi-quantificational technique.

Has anyone done a proper rou

Re: Re: NIST SRM656 Analysis

[Matthew Rowles]

Hi Tony

I can't reproduce the certificate values. This is the entire point of my
question.

Matthew

On Fri, 29 Apr 2022, 08:31 iangie,  wrote:

> Dear Mathew,
>
> Understood these values are from the SRM certificate.
> My .pro of the data suggests ~92% alpha, 3% beta, and ~5% Amorphous:
> https://www.dropbox.com/s/r2l4y0iq7d4baj7/ROW.pro?dl=0
> Can you reproduce those values on the certificate?
>
> Cheers!
>
> --
> *Dr. Xiaodong (Tony) Wang*
> *Senior Research Infrastructure Specialist (XRD)*
> Central Analytical Research Facility (CARF)   |  Queensland University of
> Technology
> *Address:* Level 6, P Block, Gardens Point campus, 2 George St Brisbane
> QLD 4000
> *Tel:* +61 7 3138 1904  |   *Mob:* 0452 571 680
> *Email:*   tony .
> w...@qut.edu.au|
>   *Web:* www.qut.edu.au/ife/carf
>
>
> 在 2022-04-27 15:55:28，"Matthew Rowles"  写道：
>
> Yep.
>
> The sample is supposed to contain 87.4 wt% alpha-Si3N4, 3.0 wt% beta-Si3N4
> and 9.6 wt% amorphous.
>
> Matthew
>
> On Tue, 26 Apr 2022 at 20:06, Martin Vickers  wrote:
>
>> Just a point of interest you seem to have a few impurity peaks
>> possibly from Si6N8 (COD entry 96-210-2554 seems to match well). it's not a
>> lot but  you might want to include that phase in your quantitative
>> calculations.
>>
>> Regards,
>>
>> Martin
>>
>>
>> --
>> Martin Vickers
>> Dept. of Chemistry, UCL,
>> 20, Gordon Street
>> WC1H 0AJ
>> 020 7679 5592 (or ex 25592)
>>
>
++
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Send commands to  eg: HELP as the subject with no body text
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++

Re: NIST SRM656 Analysis

[Matthew Rowles]

Yep.

The sample is supposed to contain 87.4 wt% alpha-Si3N4, 3.0 wt% beta-Si3N4
and 9.6 wt% amorphous.

Matthew

On Tue, 26 Apr 2022 at 20:06, Martin Vickers  wrote:

> Just a point of interest you seem to have a few impurity peaks
> possibly from Si6N8 (COD entry 96-210-2554 seems to match well). it's not a
> lot but  you might want to include that phase in your quantitative
> calculations.
>
> Regards,
>
> Martin
>
>
> --
> Martin Vickers
> Dept. of Chemistry, UCL,
> 20, Gordon Street
> WC1H 0AJ
> 020 7679 5592 (or ex 25592)
>
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++

Re: NIST SRM656 Analysis

[Matthew Rowles]

Hi Ed

The beam is smaller than the sample over all angles. - 0.25° divergence at
250 mm radius. I also collected in constant divergence mode, so the
diffracting volume is a constant.

Matthew

On Fri, 15 Apr 2022 at 01:20, Edward Laitila  wrote:

> Just curious, is the sample as prepared in the holder wider than the beam
> width at 10 degrees where you start the scan? This is a common issue that
> not many realize that for quantitative analysis the diffracting volume is
> constant provided the sample is larger than the beam in the tube and
> detector plane. If the beam is larger than the sample at these
> angles you no longer have a constant diffracting volume and hence errors in
> the analysis. I am not sure many of the  manufactures realize this based on
> personal experience with default settings of optics for some
> instruments being much too large. Additionally, background is a major issue
> as I have found especially with amorphous materials present background
> algorithms do not do a very good job and often create the background by
> hand.
>
> Regards,
> Ed
>
> On Tue, Apr 12, 2022 at 5:14 AM Matthew Rowles  wrote:
>
>> Hi all
>>
>> I've collected some more data, and am still getting spurious results, and
>> by spurious, I mean -5 wt% amorphous in SRM-alpha-656 when quantified by
>> the external method against SRM 676a.
>>
>> We had some SRM-656alpha (couldn't find any of the beta) stored in a
>> drying oven, and some SRM676a stored in a cupboard. I collected some data
>> using a D8 with Ni-filtered Cu and a lynx-eye detector (0.25° fixed
>> divergence, 250 mm radius, 2x2.5° sollers). The patterns were collected
>> consecutively (using the same program), with a single peak from SRM1976 (b,
>> I think), acting as an intensity calibrant (the intensity didn't
>> appreciably change), collected before, after, and between.
>>
>> Does anybody want to have a look at the data and see what I'm doing
>> wrong? Data available at:
>>
>> https://raw.githubusercontent.com/rowlesmr/pdCIFplotter/changing-str-to-float-conversion/data/row_Cu_676a.xy
>>
>>
>> https://raw.githubusercontent.com/rowlesmr/pdCIFplotter/changing-str-to-float-conversion/data/row_Cu_al656.xy
>>
>>
>> Thanks
>>
>> Matthew
>>
>>
>>
>>
>>
>> On Wed, 16 Mar 2022 at 21:13, Matthew Rowles  wrote:
>>
>>> Hi List People
>>>
>>> Do any of you use NIST SRM656 in your quantitative analysis quality
>>> control?
>>>
>>> I've recently started at a new lab, and am finding it impossible to make
>>> a physically realistic model (in Topas) that gives results anywhere near
>>> correct (or at least, close to the certificate values).
>>>
>>> As an example, using the external std approach with SRM676, I've managed
>>> to calculate there is -11 wt% amorphous in the beta-656 standard.
>>>
>>> I've tried using the silicon nitride structures given in the SRM
>>> certificate, but the papers and the ICSD entries don't list any thermal
>>> parameters.
>>>
>>> I can get the same results as given on the certificate using a siroquant
>>> model, but I don't know the provenance of the HKL files used in the
>>> analysis.
>>>
>>>
>>> Thanks in advance
>>>
>>>
>>> Matthew Rowles
>>>
>> ++
>> Please do NOT attach files to the whole list > >
>> Send commands to  eg: HELP as the subject with no body
>> text
>> The Rietveld_L list archive is on
>> http://www.mail-archive.com/rietveld_l@ill.fr/
>> ++
>>
>>
>
> --
> Dr. Edward A. Laitila
> Senior Research Engineer/Scientist II/Adjunct Assistant Professor
> Michigan Technological University
> Dept. of MSE
> Room 628 M Building
> (906) 369-2041
>
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
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++

Re: NIST SRM656 Analysis

[Matthew Rowles]

Hi Holger

There is a good paper by Ian Madsen, Nikki Scarlett, and Arnt Kern about
the quantification of amorphous materials -
https://doi.org/10.1524/zkri.2011.1437

On the RR, I'll let the CPD know!

Matthew

On Thu, 14 Apr 2022 at 16:51, Holger Kletti 
wrote:

> an actual RR on amourphous contents like thos on crystalline mixtureswould
> really be appriciable, i don't know any publications therewith. The problem
> seems to exist as can be seen here, but also with internal standard method,
> as in personal discussions the question on achieved negative amorphous
> contents (internal as well as external standard method) arises from time to
> time. And not alway this can be solved just by variation of background
> polynoms or other structure related parameters.
>
> So if "anyone" would initiate such a RR i would like to join it 
>
> Holger
> Am 14.04.2022 um 09:49 schrieb Julian Richard Tolchard:
>
> I confess that this discussion seems to validate my personal choice to
> treat Rietveld quantification (and especially amorphous quant) as something
> lying between a quantificational and semi-quantificational technique.
>
>
>
> Has anyone done a proper round-robin on amorphous quant (by any methods
> actually)? There have been some RR’s for crystalline mixtures I know, but I
> can’t remember seeing one for crystalline+amorphous samples.
>
>
>
>
>
> jools
>
>
>
> *From:* rietveld_l-requ...@ill.fr 
>  *On Behalf Of *Matthew Rowles
> *Sent:* torsdag 14. april 2022 09:03
> *To:* Jonathan WRIGHT  
> *Cc:* RIETVELD_L Distribution List  
> *Subject:* Re: NIST SRM656 Analysis
>
>
>
> Hi Jon
>
>
>
> The data is put on an absolute scale through the external standard
> approach. The calculations assume that the QPA for corundum in NIST
> SRSM676a is 99.02 wt%. This scaling factor is then applied to the silicon
> nitride pattern.
>
>
>
> re surface roughness: The samples were backpacked against a glass surface,
> and the powders used as-received. I've never measured the particle size
> distribution of either (any!) SRM, but the certificates describe 676a as
> "fully disaggregated" and "grains are sub-micrometer in size and equi-axial
> in shape" and the 656 certificate has a particle size distribution by laser
> scattering, with 100% less than 5 um. In our other work, we aim to
> micronise to less than 10 um. Our grinding checks show that we get 100 vol%
> <15 um and 95 vol% <6 um.
>
>
>
> I've never used the Pitschke or Suortti roughness corrections available in
> Topas, and have no intuition as to the magnitude of their correction or
> what "proper" values should be.
>
>
>
>
>
> Matthew
>
>
>
>
>
> On Wed, 13 Apr 2022 at 18:11, Jonathan WRIGHT  wrote:
>
> Maybe a silly question: are you assuming you have the data on an absolute
> scale
> in order to do these calculations? Do things like surface roughness
> somehow not
> matter?
>
> Best
>
> Jon
>
>
>
>
> On 13/04/2022 11:56, Matthew Rowles wrote:
> > Thanks Tony
> >
> > When I add the absorption edge correction to the silicon nitride model
> (and add
> > beta-silicon nitride), it becomes -2.8 wt% amorphous; up a little due to
> the
> > added correction and down a little due to the extra phase.
> >
> > If I change your al-SN thermals from 1 to those given in ICSD 77811, I
> get +4.8
> > wt% amorphous. Your atoms were already neutral, so I left them as-is.
> >
> > If I make all the Si-nitride phases' thermal parameters == 0, then I can
> get up
> > to 8.5 wt% amorphous.
> >
> > In all of this, corundum is staying as charged atoms, with Al and O beqs
> fixed
> > at 0.334 and 0.278.
> >
> > I'll have to have a go at applying the absorption edge correction; I
> always
> > forget which parameter is which thing and have to rederive my
> understanding of
> > it everytime...
> >
> >
> > Thanks
> >
> > Matthew
> >
> > On Wed, 13 Apr 2022 at 13:58, iangie  ian...@126.com>> wrote:
> >
> > Dear Matthew,
> >
> > I tried your data and get ~-1% amorphous. My .pro is in below link.
> >
> > https://www.dropbox.com/s/xuw13c91l9gq5m5/ROW.pro?dl=0
> <https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.dropbox.com%2Fs%2Fxuw13c91l9gq5m5%2FROW.pro%3Fdl%3D0=04%7C01%7Cjulianrichard.tolchard%40sintef.no%7Ced6d59fce55f4454e6a408da1de54221%7Ce1f00f39604145b0b309e0210d8b32af%7C1%7C0%7C637855168216257549%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000=fQatqp0bH0nfkYmTd8bWQkEALCntqGFYj

Re: NIST SRM656 Analysis

[Edward Laitila]

Just curious, is the sample as prepared in the holder wider than the beam
width at 10 degrees where you start the scan? This is a common issue that
not many realize that for quantitative analysis the diffracting volume is
constant provided the sample is larger than the beam in the tube and
detector plane. If the beam is larger than the sample at these
angles you no longer have a constant diffracting volume and hence errors in
the analysis. I am not sure many of the  manufactures realize this based on
personal experience with default settings of optics for some
instruments being much too large. Additionally, background is a major issue
as I have found especially with amorphous materials present background
algorithms do not do a very good job and often create the background by
hand.

Regards,
Ed

On Tue, Apr 12, 2022 at 5:14 AM Matthew Rowles  wrote:

> Hi all
>
> I've collected some more data, and am still getting spurious results, and
> by spurious, I mean -5 wt% amorphous in SRM-alpha-656 when quantified by
> the external method against SRM 676a.
>
> We had some SRM-656alpha (couldn't find any of the beta) stored in a
> drying oven, and some SRM676a stored in a cupboard. I collected some data
> using a D8 with Ni-filtered Cu and a lynx-eye detector (0.25° fixed
> divergence, 250 mm radius, 2x2.5° sollers). The patterns were collected
> consecutively (using the same program), with a single peak from SRM1976 (b,
> I think), acting as an intensity calibrant (the intensity didn't
> appreciably change), collected before, after, and between.
>
> Does anybody want to have a look at the data and see what I'm doing wrong?
> Data available at:
>
> https://raw.githubusercontent.com/rowlesmr/pdCIFplotter/changing-str-to-float-conversion/data/row_Cu_676a.xy
>
>
> https://raw.githubusercontent.com/rowlesmr/pdCIFplotter/changing-str-to-float-conversion/data/row_Cu_al656.xy
>
>
> Thanks
>
> Matthew
>
>
>
>
>
> On Wed, 16 Mar 2022 at 21:13, Matthew Rowles  wrote:
>
>> Hi List People
>>
>> Do any of you use NIST SRM656 in your quantitative analysis quality
>> control?
>>
>> I've recently started at a new lab, and am finding it impossible to make
>> a physically realistic model (in Topas) that gives results anywhere near
>> correct (or at least, close to the certificate values).
>>
>> As an example, using the external std approach with SRM676, I've managed
>> to calculate there is -11 wt% amorphous in the beta-656 standard.
>>
>> I've tried using the silicon nitride structures given in the SRM
>> certificate, but the papers and the ICSD entries don't list any thermal
>> parameters.
>>
>> I can get the same results as given on the certificate using a siroquant
>> model, but I don't know the provenance of the HKL files used in the
>> analysis.
>>
>>
>> Thanks in advance
>>
>>
>> Matthew Rowles
>>
> ++
> Please do NOT attach files to the whole list  >
> Send commands to  eg: HELP as the subject with no body
> text
> The Rietveld_L list archive is on
> http://www.mail-archive.com/rietveld_l@ill.fr/
> ++
>
>

-- 
Dr. Edward A. Laitila
Senior Research Engineer/Scientist II/Adjunct Assistant Professor
Michigan Technological University
Dept. of MSE
Room 628 M Building
(906) 369-2041
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++

Re: NIST SRM656 Analysis

[Holger Kletti]

an actual RR on amourphous contents like thos on crystalline 
mixtureswould really be appriciable, i don't know any publications 
therewith. The problem seems to exist as can be seen here, but also with 
internal standard method, as in personal discussions the question on 
achieved negative amorphous contents (internal as well as external 
standard method) arises from time to time. And not alway this can be 
solved just by variation of background polynoms or other structure 
related parameters.


So if "anyone" would initiate such a RR i would like to join it 

Holger

Am 14.04.2022 um 09:49 schrieb Julian Richard Tolchard:


I confess that this discussion seems to validate my personal choice to 
treat Rietveld quantification (and especially amorphous quant) as 
something lying between a quantificational and semi-quantificational 
technique.


Has anyone done a proper round-robin on amorphous quant (by any 
methods actually)? There have been some RR’s for crystalline mixtures 
I know, but I can’t remember seeing one for crystalline+amorphous 
samples.


jools

*From:*rietveld_l-requ...@ill.fr  *On 
Behalf Of *Matthew Rowles

*Sent:* torsdag 14. april 2022 09:03
*To:* Jonathan WRIGHT 
*Cc:* RIETVELD_L Distribution List 
*Subject:* Re: NIST SRM656 Analysis

Hi Jon

The data is put on an absolute scale through the external standard 
approach. The calculations assume that the QPA for corundum in NIST 
SRSM676a is 99.02 wt%. This scaling factor is then applied to the 
silicon nitride pattern.


re surface roughness: The samples were backpacked against a glass 
surface, and the powders used as-received. I've never measured the 
particle size distribution of either (any!) SRM, but the certificates 
describe 676a as "fully disaggregated" and "grains are sub-micrometer 
in size and equi-axial in shape" and the 656 certificate has a 
particle size distribution by laser scattering, with 100% less than 5 
um. In our other work, we aim to micronise to less than 10 um. Our 
grinding checks show that we get 100 vol% <15 um and 95 vol% <6 um.


I've never used the Pitschke or Suortti roughness corrections 
available in Topas, and have no intuition as to the magnitude of their 
correction or what "proper" values should be.


Matthew

On Wed, 13 Apr 2022 at 18:11, Jonathan WRIGHT  wrote:

Maybe a silly question: are you assuming you have the data on an
absolute scale
in order to do these calculations? Do things like surface
roughness somehow not
matter?

Best

Jon




On 13/04/2022 11:56, Matthew Rowles wrote:
> Thanks Tony
>
> When I add the absorption edge correction to the silicon nitride
model (and add
> beta-silicon nitride), it becomes -2.8 wt% amorphous; up a
little due to the
> added correction and down a little due to the extra phase.
>
> If I change your al-SN thermals from 1 to those given in
ICSD 77811, I get +4.8
> wt% amorphous. Your atoms were already neutral, so I left them
as-is.
>
> If I make all the Si-nitride phases' thermal parameters == 0,
then I can get up
> to 8.5 wt% amorphous.
>
> In all of this, corundum is staying as charged atoms, with Al
and O beqs fixed
> at 0.334 and 0.278.
>
> I'll have to have a go at applying the absorption edge
correction; I always
> forget which parameter is which thing and have to rederive my
understanding of
> it everytime...
>
>
> Thanks
>
> Matthew
>
> On Wed, 13 Apr 2022 at 13:58, iangie mailto:ian...@126.com>> wrote:
>
>     Dear Matthew,
>
>     I tried your data and get ~-1% amorphous. My .pro is in
below link.
>
> https://www.dropbox.com/s/xuw13c91l9gq5m5/ROW.pro?dl=0

<https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.dropbox.com%2Fs%2Fxuw13c91l9gq5m5%2FROW.pro%3Fdl%3D0=04%7C01%7Cjulianrichard.tolchard%40sintef.no%7Ced6d59fce55f4454e6a408da1de54221%7Ce1f00f39604145b0b309e0210d8b32af%7C1%7C0%7C637855168216257549%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000=fQatqp0bH0nfkYmTd8bWQkEALCntqGFYjYoSOXMt5ng%3D=0>
>     <https://www.dropbox.com/s/xuw13c91l9gq5m5/ROW.pro?dl=0

<https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.dropbox.com%2Fs%2Fxuw13c91l9gq5m5%2FROW.pro%3Fdl%3D0=04%7C01%7Cjulianrichard.tolchard%40sintef.no%7Ced6d59fce55f4454e6a408da1de54221%7Ce1f00f39604145b0b309e0210d8b32af%7C1%7C0%7C637855168216267509%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000=5LLaS0ghYvZKqLDm%2FSkFKRH6ltta7LOvKEb84CZnD8A%3D=0>>
>
>     I normally do not refine Beq, which I believe gives biggest
source of error
>     in QPA...
>
&

Re: NIST SRM656 Analysis

[Matthew Rowles]

Hi Jon

The data is put on an absolute scale through the external standard
approach. The calculations assume that the QPA for corundum in NIST
SRSM676a is 99.02 wt%. This scaling factor is then applied to the silicon
nitride pattern.

re surface roughness: The samples were backpacked against a glass surface,
and the powders used as-received. I've never measured the particle size
distribution of either (any!) SRM, but the certificates describe 676a as
"fully disaggregated" and "grains are sub-micrometer in size and equi-axial
in shape" and the 656 certificate has a particle size distribution by laser
scattering, with 100% less than 5 um. In our other work, we aim to
micronise to less than 10 um. Our grinding checks show that we get 100 vol%
<15 um and 95 vol% <6 um.

I've never used the Pitschke or Suortti roughness corrections available in
Topas, and have no intuition as to the magnitude of their correction or
what "proper" values should be.


Matthew


On Wed, 13 Apr 2022 at 18:11, Jonathan WRIGHT  wrote:

> Maybe a silly question: are you assuming you have the data on an absolute
> scale
> in order to do these calculations? Do things like surface roughness
> somehow not
> matter?
>
> Best
>
> Jon
>
>
>
>
> On 13/04/2022 11:56, Matthew Rowles wrote:
> > Thanks Tony
> >
> > When I add the absorption edge correction to the silicon nitride model
> (and add
> > beta-silicon nitride), it becomes -2.8 wt% amorphous; up a little due to
> the
> > added correction and down a little due to the extra phase.
> >
> > If I change your al-SN thermals from 1 to those given in ICSD 77811, I
> get +4.8
> > wt% amorphous. Your atoms were already neutral, so I left them as-is.
> >
> > If I make all the Si-nitride phases' thermal parameters == 0, then I can
> get up
> > to 8.5 wt% amorphous.
> >
> > In all of this, corundum is staying as charged atoms, with Al and O beqs
> fixed
> > at 0.334 and 0.278.
> >
> > I'll have to have a go at applying the absorption edge correction; I
> always
> > forget which parameter is which thing and have to rederive my
> understanding of
> > it everytime...
> >
> >
> > Thanks
> >
> > Matthew
> >
> > On Wed, 13 Apr 2022 at 13:58, iangie  ian...@126.com>> wrote:
> >
> > Dear Matthew,
> >
> > I tried your data and get ~-1% amorphous. My .pro is in below link.
> >
> > https://www.dropbox.com/s/xuw13c91l9gq5m5/ROW.pro?dl=0
> > 
> >
> > I normally do not refine Beq, which I believe gives biggest source
> of error
> > in QPA...
> >
> >
> > Cheers!
> >
> > --
> >
> > *Dr. Xiaodong (Tony) Wang*
> > *Senior Research Infrastructure Specialist (XRD)*
> > Central Analytical Research Facility (CARF)   |  Queensland
> University of
> > Technology
> > *Address:* Level 6, P Block, Gardens Point campus, 2 George St
> Brisbane QLD 4000
> > *Tel:*+61 7 3138 1904  | *Mob:*0452 571 680
> > *Email:* tony .
> > w...@qut.edu.au
> >    | *Web:*
> www.qut.edu.au/ife/carf
> > 
> >
> >
> > At 2022-04-13 13:00:44, "Matthew Rowles"  > > wrote:
> >
> > Hi all
> >
> > Thanks to those that have replied off-list.
> >
> > I've managed to jiggle things around and get various answers. If
> you
> > want an answer between -14 and +6 wt% amorphous, I can make it
> happen. I
> > can either use charged atoms or not, or use thermal parameters
> or not.
> > Combining those between the corundum and Si3N4, you get the
> following:
> >
> >
> > image.png
> > This is using the scattering factors defined with 11 gaussians.
> >
> > If you use the ones defined by 9 gaussians, you get
> > image.png
> >
> > The structures I used are below. In the certificate for 656, the
> > structures are referenced, but those structures have no thermal
> > parameters. Does anyone know what was used in the NIST
> determination?
> >
> >
> >
> > phase_name "Aluminium_oxide_alpha_10425_icsd"
> > Hexagonal( 4.759355, 12.99231)
> > space_group "R -3 c H"
> > site Al1 num_posns  12x 0  y 0 z 0.14772 occ Al+3 1. beq
> 0.318
> > site O1  num_posns  18x 0.3064 y 0 z 0.25occ O-2  1. beq
> 0.334
> >
> > phase_name "ALPHA_Marchand_ICSD_26191"
> > Hexagonal( 7.75411, 5.62034)
> > space_group "P31c" 'atom positions from Marchand. Thermals from
> ICSD 77811
> > site Si1 num_posns  6x 0.0806 y 0.5095 z 0.3020 occ Si+4 1   beq
> 0.25
> > site Si2 num_posns  6x 0.1675 y 0.2560 z 0.0070 occ Si+4 1   beq
> 0.29
> > site N1  num_posns  2x 0  y 0  z 0  occ N1.  beq
> 0.88
> > site N2  num_posns  2x =1/3;  y =2/3;  z 0.3500 occ N1.  beq
> 0.46
> > site N3  

Re: NIST SRM656 Analysis

[Jonathan WRIGHT]

Maybe a silly question: are you assuming you have the data on an absolute scale 
in order to do these calculations? Do things like surface roughness somehow not 
matter?


Best

Jon




On 13/04/2022 11:56, Matthew Rowles wrote:

Thanks Tony

When I add the absorption edge correction to the silicon nitride model (and add 
beta-silicon nitride), it becomes -2.8 wt% amorphous; up a little due to the 
added correction and down a little due to the extra phase.


If I change your al-SN thermals from 1 to those given in ICSD 77811, I get +4.8 
wt% amorphous. Your atoms were already neutral, so I left them as-is.


If I make all the Si-nitride phases' thermal parameters == 0, then I can get up 
to 8.5 wt% amorphous.


In all of this, corundum is staying as charged atoms, with Al and O beqs fixed 
at 0.334 and 0.278.


I'll have to have a go at applying the absorption edge correction; I always 
forget which parameter is which thing and have to rederive my understanding of 
it everytime...



Thanks

Matthew

On Wed, 13 Apr 2022 at 13:58, iangie mailto:ian...@126.com>> 
wrote:

Dear Matthew,

I tried your data and get ~-1% amorphous. My .pro is in below link.

https://www.dropbox.com/s/xuw13c91l9gq5m5/ROW.pro?dl=0


I normally do not refine Beq, which I believe gives biggest source of error
in QPA...


Cheers!

--

*Dr. Xiaodong (Tony) Wang*
*Senior Research Infrastructure Specialist (XRD)*
Central Analytical Research Facility (CARF)   |  Queensland University of
Technology
*Address:* Level 6, P Block, Gardens Point campus, 2 George St Brisbane QLD 
4000
*Tel:*+61 7 3138 1904  | *Mob:*0452 571 680
*Email:* tony .
w...@qut.edu.au
   | *Web:* www.qut.edu.au/ife/carf



At 2022-04-13 13:00:44, "Matthew Rowles" mailto:rowle...@gmail.com>> wrote:

Hi all

Thanks to those that have replied off-list.

I've managed to jiggle things around and get various answers. If you
want an answer between -14 and +6 wt% amorphous, I can make it happen. I
can either use charged atoms or not, or use thermal parameters or not.
Combining those between the corundum and Si3N4, you get the following:


image.png
This is using the scattering factors defined with 11 gaussians.

If you use the ones defined by 9 gaussians, you get
image.png

The structures I used are below. In the certificate for 656, the
structures are referenced, but those structures have no thermal
parameters. Does anyone know what was used in the NIST determination?



phase_name "Aluminium_oxide_alpha_10425_icsd"
Hexagonal( 4.759355, 12.99231)
space_group "R -3 c H"
site Al1 num_posns  12x 0      y 0 z 0.14772 occ Al+3 1. beq  0.318
site O1  num_posns  18x 0.3064 y 0 z 0.25    occ O-2  1. beq  0.334

phase_name "ALPHA_Marchand_ICSD_26191"
Hexagonal( 7.75411, 5.62034)
space_group "P31c" 'atom positions from Marchand. Thermals from ICSD 
77811
site Si1 num_posns  6x 0.0806 y 0.5095 z 0.3020 occ Si+4 1   beq 0.25
site Si2 num_posns  6x 0.1675 y 0.2560 z 0.0070 occ Si+4 1   beq 0.29
site N1  num_posns  2x 0      y 0      z 0      occ N    1.  beq 0.88
site N2  num_posns  2x =1/3;  y =2/3;  z 0.3500 occ N    1.  beq 0.46
site N3  num_posns  6x 0.0390 y 0.3860 z 0.0310 occ N    1.  beq 1.06
site N4  num_posns  6x 0.3190 y 0.3210 z 0.2660 occ N    1.  beq 0.17

phase_name "BETA_Billy_ICSD_35566"
Hexagonal( 7.60633, 2.90778)
space_group "P 63/m" ' structure from Billy, thermals from ICSD 170004
site Si1 num_posns  6x 0.2323 y 0.4096 z 0.25 occ Si+4   1  beq 0.231
site N1  num_posns  2x =1/3;  y =2/3;  z 0.25 occ N      1  beq 0.326
site N2  num_posns  6x 0.3337 y 0.0323 z 0.25 occ N      1  beq 0.314






On Tue, 12 Apr 2022 at 17:13, Matthew Rowles mailto:rowle...@gmail.com>> wrote:

Hi all

I've collected some more data, and am still getting spurious
results, and by spurious, I mean -5 wt% amorphous in SRM-alpha-656
when quantified by the external method against SRM 676a.

We had some SRM-656alpha (couldn't find any of the beta) stored in a
drying oven, and some SRM676a stored in a cupboard. I collected some
data using a D8 with Ni-filtered Cu and a lynx-eye detector (0.25°
fixed divergence, 250 mm radius, 2x2.5° sollers). The patterns were
collected consecutively (using the same program), with a single peak
from SRM1976 (b, I think), acting as an intensity calibrant (the
intensity didn't appreciably change), 

Re: Re: NIST SRM656 Analysis

[Matthew Rowles]

Thanks Tony

When I add the absorption edge correction to the silicon nitride model (and
add beta-silicon nitride), it becomes -2.8 wt% amorphous; up a little due
to the added correction and down a little due to the extra phase.

If I change your al-SN thermals from 1 to those given in ICSD 77811, I
get +4.8 wt% amorphous. Your atoms were already neutral, so I left them
as-is.

If I make all the Si-nitride phases' thermal parameters == 0, then I can
get up to 8.5 wt% amorphous.

In all of this, corundum is staying as charged atoms, with Al and O beqs
fixed at 0.334 and 0.278.

I'll have to have a go at applying the absorption edge correction; I always
forget which parameter is which thing and have to rederive my understanding
of it everytime...


Thanks

Matthew

On Wed, 13 Apr 2022 at 13:58, iangie  wrote:

> Dear Matthew,
>
> I tried your data and get ~-1% amorphous. My .pro is in below link.
>
> https://www.dropbox.com/s/xuw13c91l9gq5m5/ROW.pro?dl=0
>
> I normally do not refine Beq, which I believe gives biggest source of
> error in QPA...
>
>
> Cheers!
>
> --
> *Dr. Xiaodong (Tony) Wang*
> *Senior Research Infrastructure Specialist (XRD)*
> Central Analytical Research Facility (CARF)   |  Queensland University of
> Technology
> *Address:* Level 6, P Block, Gardens Point campus, 2 George St Brisbane
> QLD 4000
> *Tel:* +61 7 3138 1904  |   *Mob:* 0452 571 680
> *Email:*   tony .
> w...@qut.edu.au|
>   *Web:* www.qut.edu.au/ife/carf
>
>
> At 2022-04-13 13:00:44, "Matthew Rowles"  wrote:
>
> Hi all
>
> Thanks to those that have replied off-list.
>
> I've managed to jiggle things around and get various answers. If you want
> an answer between -14 and +6 wt% amorphous, I can make it happen. I can
> either use charged atoms or not, or use thermal parameters or not.
> Combining those between the corundum and Si3N4, you get the following:
>
>
> [image: image.png]
> This is using the scattering factors defined with 11 gaussians.
>
> If you use the ones defined by 9 gaussians, you get
> [image: image.png]
>
> The structures I used are below. In the certificate for 656, the
> structures are referenced, but those structures have no thermal parameters.
> Does anyone know what was used in the NIST determination?
>
>
>
> phase_name "Aluminium_oxide_alpha_10425_icsd"
> Hexagonal( 4.759355, 12.99231)
> space_group "R -3 c H"
> site Al1 num_posns  12 x 0  y 0 z 0.14772 occ Al+3 1. beq  0.318
> site O1  num_posns  18 x 0.3064 y 0 z 0.25occ O-2  1. beq  0.334
>
> phase_name "ALPHA_Marchand_ICSD_26191"
> Hexagonal( 7.75411, 5.62034)
> space_group "P31c" 'atom positions from Marchand. Thermals from ICSD 77811
> site Si1 num_posns  6 x 0.0806 y 0.5095 z 0.3020 occ Si+4 1   beq 0.25
> site Si2 num_posns  6 x 0.1675 y 0.2560 z 0.0070 occ Si+4 1   beq 0.29
> site N1  num_posns  2 x 0  y 0  z 0  occ N1.  beq 0.88
> site N2  num_posns  2 x =1/3;  y =2/3;  z 0.3500 occ N1.  beq 0.46
> site N3  num_posns  6 x 0.0390 y 0.3860 z 0.0310 occ N1.  beq 1.06
> site N4  num_posns  6 x 0.3190 y 0.3210 z 0.2660 occ N1.  beq 0.17
>
> phase_name "BETA_Billy_ICSD_35566"
> Hexagonal( 7.60633, 2.90778)
> space_group "P 63/m" ' structure from Billy, thermals from ICSD 170004
> site Si1 num_posns  6 x 0.2323 y 0.4096 z 0.25 occ Si+4   1  beq 0.231
> site N1  num_posns  2 x =1/3;  y =2/3;  z 0.25 occ N  1  beq 0.326
> site N2  num_posns  6 x 0.3337 y 0.0323 z 0.25 occ N  1  beq 0.314
>
>
>
>
>
>
> On Tue, 12 Apr 2022 at 17:13, Matthew Rowles  wrote:
>
>> Hi all
>>
>> I've collected some more data, and am still getting spurious results, and
>> by spurious, I mean -5 wt% amorphous in SRM-alpha-656 when quantified by
>> the external method against SRM 676a.
>>
>> We had some SRM-656alpha (couldn't find any of the beta) stored in a
>> drying oven, and some SRM676a stored in a cupboard. I collected some data
>> using a D8 with Ni-filtered Cu and a lynx-eye detector (0.25° fixed
>> divergence, 250 mm radius, 2x2.5° sollers). The patterns were collected
>> consecutively (using the same program), with a single peak from SRM1976 (b,
>> I think), acting as an intensity calibrant (the intensity didn't
>> appreciably change), collected before, after, and between.
>>
>> Does anybody want to have a look at the data and see what I'm doing
>> wrong? Data available at:
>>
>> https://raw.githubusercontent.com/rowlesmr/pdCIFplotter/changing-str-to-float-conversion/data/row_Cu_676a.xy
>>
>>
>> https://raw.githubusercontent.com/rowlesmr/pdCIFplotter/changing-str-to-float-conversion/data/row_Cu_al656.xy
>>
>>
>> Thanks
>>
>> Matthew
>>
>>
>>
>>
>>
>> On Wed, 16 Mar 2022 at 21:13, Matthew Rowles  wrote:
>>
>>> Hi List People
>>>
>>> Do any of you use NIST SRM656 in your quantitative analysis quality
>>> control?
>>>
>>> I've recently started at a new lab, and am finding it impossible to make
>>> a physically realistic model (in Topas) that gives results anywhere near
>>> correct (or at least, close to the certificate 

Re: NIST SRM656 Analysis

[Alan W Hewat]

Thanks Mathew, for the summary of the replies you received off-list.

Just a remark to those who reply off-list. The purpose of the Rietveld list
is to facilitate discussion. That can't happen if the conversation is
off-list.

Alan

Dr Alan Hewat, NeutronOptics
Grenoble, FRANCE (from phone)
alan.he...@neutronoptics.com
+33.476984168 VAT:FR79499450856
http://NeutronOptics.com/hewat
___


On Wed, 13 Apr 2022, 07:01 Matthew Rowles,  wrote:

> Hi all
>
> Thanks to those that have replied off-list.
>
> I've managed to jiggle things around and get various answers. If you want
> an answer between -14 and +6 wt% amorphous, I can make it happen. I can
> either use charged atoms or not, or use thermal parameters or not.
> Combining those between the corundum and Si3N4, you get the following:
>
>
> [image: image.png]
> This is using the scattering factors defined with 11 gaussians.
>
> If you use the ones defined by 9 gaussians, you get
> [image: image.png]
>
> The structures I used are below. In the certificate for 656, the
> structures are referenced, but those structures have no thermal parameters.
> Does anyone know what was used in the NIST determination?
>
>
>
> phase_name "Aluminium_oxide_alpha_10425_icsd"
> Hexagonal( 4.759355, 12.99231)
> space_group "R -3 c H"
> site Al1 num_posns  12 x 0  y 0 z 0.14772 occ Al+3 1. beq  0.318
> site O1  num_posns  18 x 0.3064 y 0 z 0.25occ O-2  1. beq  0.334
>
> phase_name "ALPHA_Marchand_ICSD_26191"
> Hexagonal( 7.75411, 5.62034)
> space_group "P31c" 'atom positions from Marchand. Thermals from ICSD 77811
> site Si1 num_posns  6 x 0.0806 y 0.5095 z 0.3020 occ Si+4 1   beq 0.25
> site Si2 num_posns  6 x 0.1675 y 0.2560 z 0.0070 occ Si+4 1   beq 0.29
> site N1  num_posns  2 x 0  y 0  z 0  occ N1.  beq 0.88
> site N2  num_posns  2 x =1/3;  y =2/3;  z 0.3500 occ N1.  beq 0.46
> site N3  num_posns  6 x 0.0390 y 0.3860 z 0.0310 occ N1.  beq 1.06
> site N4  num_posns  6 x 0.3190 y 0.3210 z 0.2660 occ N1.  beq 0.17
>
> phase_name "BETA_Billy_ICSD_35566"
> Hexagonal( 7.60633, 2.90778)
> space_group "P 63/m" ' structure from Billy, thermals from ICSD 170004
> site Si1 num_posns  6 x 0.2323 y 0.4096 z 0.25 occ Si+4   1  beq 0.231
> site N1  num_posns  2 x =1/3;  y =2/3;  z 0.25 occ N  1  beq 0.326
> site N2  num_posns  6 x 0.3337 y 0.0323 z 0.25 occ N  1  beq 0.314
>
>
>
>
>
>
> On Tue, 12 Apr 2022 at 17:13, Matthew Rowles  wrote:
>
>> Hi all
>>
>> I've collected some more data, and am still getting spurious results, and
>> by spurious, I mean -5 wt% amorphous in SRM-alpha-656 when quantified by
>> the external method against SRM 676a.
>>
>> We had some SRM-656alpha (couldn't find any of the beta) stored in a
>> drying oven, and some SRM676a stored in a cupboard. I collected some data
>> using a D8 with Ni-filtered Cu and a lynx-eye detector (0.25° fixed
>> divergence, 250 mm radius, 2x2.5° sollers). The patterns were collected
>> consecutively (using the same program), with a single peak from SRM1976 (b,
>> I think), acting as an intensity calibrant (the intensity didn't
>> appreciably change), collected before, after, and between.
>>
>> Does anybody want to have a look at the data and see what I'm doing
>> wrong? Data available at:
>>
>> https://raw.githubusercontent.com/rowlesmr/pdCIFplotter/changing-str-to-float-conversion/data/row_Cu_676a.xy
>>
>>
>> https://raw.githubusercontent.com/rowlesmr/pdCIFplotter/changing-str-to-float-conversion/data/row_Cu_al656.xy
>>
>>
>> Thanks
>>
>> Matthew
>>
>>
>>
>>
>>
>> On Wed, 16 Mar 2022 at 21:13, Matthew Rowles  wrote:
>>
>>> Hi List People
>>>
>>> Do any of you use NIST SRM656 in your quantitative analysis quality
>>> control?
>>>
>>> I've recently started at a new lab, and am finding it impossible to make
>>> a physically realistic model (in Topas) that gives results anywhere near
>>> correct (or at least, close to the certificate values).
>>>
>>> As an example, using the external std approach with SRM676, I've managed
>>> to calculate there is -11 wt% amorphous in the beta-656 standard.
>>>
>>> I've tried using the silicon nitride structures given in the SRM
>>> certificate, but the papers and the ICSD entries don't list any thermal
>>> parameters.
>>>
>>> I can get the same results as given on the certificate using a siroquant
>>> model, but I don't know the provenance of the HKL files used in the
>>> analysis.
>>>
>>>
>>> Thanks in advance
>>>
>>>
>>> Matthew Rowles
>>>
>> ++
> Please do NOT attach files to the whole list  >
> Send commands to  eg: HELP as the subject with no body
> text
> The Rietveld_L list archive is on
> http://www.mail-archive.com/rietveld_l@ill.fr/
> ++
>
>
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP 

Re: NIST SRM656 Analysis

[Matthew Rowles]

Hi all

Thanks to those that have replied off-list.

I've managed to jiggle things around and get various answers. If you want
an answer between -14 and +6 wt% amorphous, I can make it happen. I can
either use charged atoms or not, or use thermal parameters or not.
Combining those between the corundum and Si3N4, you get the following:


[image: image.png]
This is using the scattering factors defined with 11 gaussians.

If you use the ones defined by 9 gaussians, you get
[image: image.png]

The structures I used are below. In the certificate for 656, the structures
are referenced, but those structures have no thermal parameters. Does
anyone know what was used in the NIST determination?



phase_name "Aluminium_oxide_alpha_10425_icsd"
Hexagonal( 4.759355, 12.99231)
space_group "R -3 c H"
site Al1 num_posns  12 x 0  y 0 z 0.14772 occ Al+3 1. beq  0.318
site O1  num_posns  18 x 0.3064 y 0 z 0.25occ O-2  1. beq  0.334

phase_name "ALPHA_Marchand_ICSD_26191"
Hexagonal( 7.75411, 5.62034)
space_group "P31c" 'atom positions from Marchand. Thermals from ICSD 77811
site Si1 num_posns  6 x 0.0806 y 0.5095 z 0.3020 occ Si+4 1   beq 0.25
site Si2 num_posns  6 x 0.1675 y 0.2560 z 0.0070 occ Si+4 1   beq 0.29
site N1  num_posns  2 x 0  y 0  z 0  occ N1.  beq 0.88
site N2  num_posns  2 x =1/3;  y =2/3;  z 0.3500 occ N1.  beq 0.46
site N3  num_posns  6 x 0.0390 y 0.3860 z 0.0310 occ N1.  beq 1.06
site N4  num_posns  6 x 0.3190 y 0.3210 z 0.2660 occ N1.  beq 0.17

phase_name "BETA_Billy_ICSD_35566"
Hexagonal( 7.60633, 2.90778)
space_group "P 63/m" ' structure from Billy, thermals from ICSD 170004
site Si1 num_posns  6 x 0.2323 y 0.4096 z 0.25 occ Si+4   1  beq 0.231
site N1  num_posns  2 x =1/3;  y =2/3;  z 0.25 occ N  1  beq 0.326
site N2  num_posns  6 x 0.3337 y 0.0323 z 0.25 occ N  1  beq 0.314






On Tue, 12 Apr 2022 at 17:13, Matthew Rowles  wrote:

> Hi all
>
> I've collected some more data, and am still getting spurious results, and
> by spurious, I mean -5 wt% amorphous in SRM-alpha-656 when quantified by
> the external method against SRM 676a.
>
> We had some SRM-656alpha (couldn't find any of the beta) stored in a
> drying oven, and some SRM676a stored in a cupboard. I collected some data
> using a D8 with Ni-filtered Cu and a lynx-eye detector (0.25° fixed
> divergence, 250 mm radius, 2x2.5° sollers). The patterns were collected
> consecutively (using the same program), with a single peak from SRM1976 (b,
> I think), acting as an intensity calibrant (the intensity didn't
> appreciably change), collected before, after, and between.
>
> Does anybody want to have a look at the data and see what I'm doing wrong?
> Data available at:
>
> https://raw.githubusercontent.com/rowlesmr/pdCIFplotter/changing-str-to-float-conversion/data/row_Cu_676a.xy
>
>
> https://raw.githubusercontent.com/rowlesmr/pdCIFplotter/changing-str-to-float-conversion/data/row_Cu_al656.xy
>
>
> Thanks
>
> Matthew
>
>
>
>
>
> On Wed, 16 Mar 2022 at 21:13, Matthew Rowles  wrote:
>
>> Hi List People
>>
>> Do any of you use NIST SRM656 in your quantitative analysis quality
>> control?
>>
>> I've recently started at a new lab, and am finding it impossible to make
>> a physically realistic model (in Topas) that gives results anywhere near
>> correct (or at least, close to the certificate values).
>>
>> As an example, using the external std approach with SRM676, I've managed
>> to calculate there is -11 wt% amorphous in the beta-656 standard.
>>
>> I've tried using the silicon nitride structures given in the SRM
>> certificate, but the papers and the ICSD entries don't list any thermal
>> parameters.
>>
>> I can get the same results as given on the certificate using a siroquant
>> model, but I don't know the provenance of the HKL files used in the
>> analysis.
>>
>>
>> Thanks in advance
>>
>>
>> Matthew Rowles
>>
>
++
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++

Re: NIST SRM656 Analysis

[Matthew Rowles]

Hi all

I've collected some more data, and am still getting spurious results, and
by spurious, I mean -5 wt% amorphous in SRM-alpha-656 when quantified by
the external method against SRM 676a.

We had some SRM-656alpha (couldn't find any of the beta) stored in a drying
oven, and some SRM676a stored in a cupboard. I collected some data using a
D8 with Ni-filtered Cu and a lynx-eye detector (0.25° fixed divergence, 250
mm radius, 2x2.5° sollers). The patterns were collected
consecutively (using the same program), with a single peak from SRM1976 (b,
I think), acting as an intensity calibrant (the intensity didn't
appreciably change), collected before, after, and between.

Does anybody want to have a look at the data and see what I'm doing wrong?
Data available at:
https://raw.githubusercontent.com/rowlesmr/pdCIFplotter/changing-str-to-float-conversion/data/row_Cu_676a.xy

https://raw.githubusercontent.com/rowlesmr/pdCIFplotter/changing-str-to-float-conversion/data/row_Cu_al656.xy


Thanks

Matthew





On Wed, 16 Mar 2022 at 21:13, Matthew Rowles  wrote:

> Hi List People
>
> Do any of you use NIST SRM656 in your quantitative analysis quality
> control?
>
> I've recently started at a new lab, and am finding it impossible to make a
> physically realistic model (in Topas) that gives results anywhere near
> correct (or at least, close to the certificate values).
>
> As an example, using the external std approach with SRM676, I've managed
> to calculate there is -11 wt% amorphous in the beta-656 standard.
>
> I've tried using the silicon nitride structures given in the SRM
> certificate, but the papers and the ICSD entries don't list any thermal
> parameters.
>
> I can get the same results as given on the certificate using a siroquant
> model, but I don't know the provenance of the HKL files used in the
> analysis.
>
>
> Thanks in advance
>
>
> Matthew Rowles
>
++
Please do NOT attach files to the whole list 
Send commands to  eg: HELP as the subject with no body text
The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/
++