Re: [Ifeffit] Fe K-edge maghemite (gamma-Fe2O3)

2024-02-08 Thread Denis TESTEMALE 
Dear Christian, 
some XES and HERFD data on maghemite in our database: 
[ https://www.sshade.eu/data/experiment/EXPERIMENT_SOC_20181115_005 | 
https://www.sshade.eu/data/experiment/EXPERIMENT_SOC_20181115_005 ] 

Cheers 
Denis 


De: "Christian Wittee Lopes"  
À: "XAFS Analysis using Ifeffit"  
Envoyé: Jeudi 8 Février 2024 20:02:02 
Objet: [Ifeffit] Fe K-edge maghemite (gamma-Fe2O3) 

Dear XAFS community, 
Does anyone have a Fe K-edge XAS spectrum of maghemite (gamma-Fe2O3) sample or 
standard? 

Thank you in advance. 

Best, 

Christian Wittee Lopes 

-- 


Christian Wittee Lopes 


Professor Adjunto 

Departamento de Química - Setor de Ciências Exatas 


Universidade Federal do Paraná (UFPR) 

Curitiba - Paraná 


[ https://www.linkedin.com/in/christian-wittee-lopes-561855219/ | LinkedIn ] | 
[ https://orcid.org/my-orcid?orcid=-0001-8420-1958 | ORCID ] | [ 
http://lattes.cnpq.br/4953371870936050 | Lattes ] 

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Re: [Ifeffit] Fe K-edge maghemite (gamma-Fe2O3)

2024-02-08 Thread Otal Eugenio 
Dear Christian,
Check this database:
https://mdr.nims.go.jp/concern/datasets/1n79h782t?locale=en
I hope it helps.
Best regards.


(^ㅇᆽㅇ^)(=˃ᆺ˂=)(= ༝ =)

Eugenio H. OTAL
Assistant Professor
Dept. of Materials Chemistry
Shinshu University
4-17-1 Wakasato, Nagano 380-8553, JAPAN
eugenio_o...@shinshu-u.ac.jp
https://sites.google.com/view/zettsu-laboratory/news-updates

¯\_(ツ)_/¯¯\_(ツ)_/¯

Who is John Galt?

¯\_(ツ)_/¯¯\_(ツ)_/¯



On Fri, Feb 9, 2024 at 4:12 AM Christian Wittee Lopes 
wrote:

> Dear XAFS community,
>
> Does anyone have a Fe K-edge XAS spectrum of maghemite (gamma-Fe2O3)
> sample or standard?
>
> Thank you in advance.
>
> Best,
>
> Christian Wittee Lopes
>
> --
>
> Christian Wittee Lopes
>
> Professor Adjunto
>
> *Departamento de Química - Setor de Ciências Exatas*
>
> Universidade Federal do Paraná (UFPR)
>
> *Curitiba - Paraná*
>
> *LinkedIn 
> | ORCID  | Lattes
> *
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Re: [Ifeffit] Fe K-edge maghemite (gamma-Fe2O3)

2024-02-08 Thread Robert Gordon 

Hi,

Average of 3 scans from APS-20BM, 2s/pt per scan...commercial powder 
(ground, Alfa?) on tape.
Data were collected in 2009. I would have to dig to find out how many 
layers...around 8...


Reference Fe foil measured simultaneously in transmission - no shift 
between scans.


Si(111), 80%-ish tune around 7.4keV...

cheers,
-R.


On 2024-02-08 11:02 a.m., Christian Wittee Lopes wrote:

Dear XAFS community,

Does anyone have a Fe K-edge XAS spectrum of maghemite (gamma-Fe2O3) 
sample or standard?


Thank you in advance.

Best,

Christian Wittee Lopes

--

Christian Wittee Lopes

Professor Adjunto

/Departamento de Química - Setor de Ciências Exatas/

Universidade Federal do Paraná (UFPR)

/Curitiba - Paraná/

/LinkedIn 
| ORCID 
| Lattes 
/



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# created: Thu Feb 08 16:49:38 2024
# from file: r-Fe2O3.0013
# No: 284  [E0: 0,0,0,-1]
#-
#   X  Y
6.9122217890E+000  2.3873525979E-001
6.9223211954E+000  2.3164588825E-001
6.9323498145E+000  2.2456452215E-001
6.9423170573E+000  2.1756838970E-001
6.9522426850E+000  2.1084974252E-001
6.9621979893E+000  2.0396161597E-001
6.9722448309E+000  1.9706588090E-001
6.9821465592E+000  1.9041022419E-001
6.9921604797E+000  1.8361093435E-001
7.0020590912E+000  1.7700662132E-001
7.0121015120E+000  1.7041316226E-001
7.0220487198E+000  1.6366768794E-001
7.0318264240E+000  1.5727851308E-001
7.0417376019E+000  1.5080703027E-001
7.0516252875E+000  1.4423514799E-001
7.0615419695E+000  1.3804722093E-001
7.0713924093E+000  1.3202582731E-001
7.0813778086E+000  1.2597846037E-001
7.0912540883E+000  1.2053001376E-001
7.1010308547E+000  1.1590367809E-001
7.1013408400E+000  1.1589968477E-001
7.1016294723E+000  1.1583510450E-001
7.1019608951E+000  1.1565987866E-001
7.1022709650E+000  1.1554434955E-001
7.1025169025E+000  1.1538424881E-001
7.1027735520E+000  1.1555100474E-001
7.1030836958E+000  1.1545374436E-001
7.1034259562E+000  1.1541521173E-001
7.1037896456E+000  1.1530363057E-001
7.1041105801E+000  1.1524828928E-001
7.1043673496E+000  1.1522977858E-001
7.1045813389E+000  1.1512092756E-001
7.1048595451E+000  1.1516503432E-001
7.1052447911E+000  1.1513521085E-001
7.1055979716E+000  1.1511001667E-001
7.1059083725E+000  1.1513839530E-001
7.1062295066E+000  1.1516503197E-001
7.1065292590E+000  1.1508938873E-001
7.1067755040E+000  1.1507978146E-001
7.1070110592E+000  1.1508875333E-001
7.1072894637E+000  1.1519326810E-001
7.1076214373E+000  1.1524191334E-001
7.1079534431E+000  1.1552987263E-001
7.1082961927E+000  1.1568739364E-001
7.1085747021E+000  1.1582230181E-001
7.1087889556E+000  1.1592800053E-001
7.1090139362E+000  1.1621977383E-001
7.1093246482E+000  1.1648145453E-001
7.1096568198E+000  1.1701166512E-001
7.1099568736E+000  1.1766040524E-001
7.1102676715E+000  1.1839233016E-001
7.1105892162E+000  1.1959170496E-001
7.1108679129E+000  1.2092582368E-001
7.144712E+000  1.2270620833E-001
7.1114039320E+000  1.2640049179E-001
7.1117470284E+000  1.3347889216E-001
7.1121008827E+000  1.4273741451E-001
7.1124440492E+000  1.5252079218E-001
7.1127550736E+000  1.6114797293E-001
7.1129695898E+000  1.6519158796E-001
7.1132163000E+000  1.6632391267E-001
7.1135595786E+000  1.6256279491E-001
7.1139458084E+000  1.5601936956E-001
7.1142569696E+000  1.5117921038E-001
7.1145788905E+000  1.4857390028E-001
7.1148793773E+000  1.4784161489E-001
7.1151584245E+000  1.4790850735E-001
7.1154052929E+000  1.4813537325E-001
7.1156629138E+000  1.4873506660E-001
7.1159634960E+000  1.4956729975E-001
7.1162963143E+000  1.5001480637E-001
7.1166399028E+000  1.5045073929E-001
7.1169727871E+000  1.5085192857E-001
7.1172090472E+000  1.5133179336E-001
7.1174238433E+000  1.5211471063E-001
7.1177030984E+000  1.5359173100E-001
7.1180360863E+000  1.5618725710E-001
7.1183368775E+000  1.5963936461E-001
7.1186484391E+000  1.6442814068E-001
7.1189600292E+000  1.7077800608E-001
7.1192609017E+000  1.7787256993E-001
7.1195403070E+000  1.8564152048E-001
7.1198089876E+000  1.9616114036E-001
7.1201206835E+000  2.1284405772E-001
7.1204754065E+000  2.3381610544E-001
7.1207979139E+000  2.5527944114E-001
7.1211527072E+000  2.8026058695E-001
7.1214215146E+000  3.0283915988E-001
7.1216473291E+000  3.2329228273E-001
7.1219269296E+000  3.4640936257E-001
7.1223033511E+000  3.7239957189E-001
7.1226583007E+000  3.9426157067E-001
7.1229810141E+000  4.1405761106E-001
7.1232929994E+000  4.3130341011E-001
7.1236050132E+000  4.4704105483E-001
7.1238524926E+000  4.6086797009E-001
7.1241107512E+000  4.7753722548E-001
7.1243797912E+000  5.0043035550E-001
7.1247026672E+000  5.2979522382E-001

Re: [Ifeffit] [Ext] weak scattering from second-nearest neighbors for single atom catalysts

2024-02-08 Thread Carlo Segre 
Hi Qiang:

It is exactly as you say.  The number of metal-metal paths is small and not
well ordered.  This washes out the scattering significantly.  If the Pt is
in a more rigid well-ordered structure the second "shell" path is generally
more visible.

Carlo

On Thu, Feb 8, 2024 at 1:08 PM Qiang  wrote:

> Hi everyone,
>
> I would like to have a discussion about the common EXAFS for single atom
> catalysts. It is usually observed that there is only one strong peak around
> 1.5A in EXAFS, and it is attributed to the nearest neighbors of O or N.
> Take an example of Pt1/CeO2 catalyst. Pt single atom is coordinated with a
> few oxygens, i.e., PtOx. These oxygens constitute the first shell of Pt. It
> is supposed that these O should also attach to the metal element of the
> support (Ce here). So there is also Pt-O-Ce structure. Why it doesnot have
> strong scattering peak in EXAFS? Is it that because the Pt-O-Ce formed is
> not ordered, or it is actually not a bond just some weak contact?
>
> Thank you very much.
>
> Qiang
>
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Professor of Materials Science & Engineering
Director, Center for Synchrotron Radiation Research and Instrumentation
Illinois Institute of Technology
Phone: 312.567.3498
se...@iit.edu   http://phys.iit.edu/~segre   se...@debian.org
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[Ifeffit] Fe K-edge maghemite (gamma-Fe2O3)

2024-02-08 Thread Christian Wittee Lopes 
Dear XAFS community,

Does anyone have a Fe K-edge XAS spectrum of maghemite (gamma-Fe2O3) sample
or standard?

Thank you in advance.

Best,

Christian Wittee Lopes

-- 

Christian Wittee Lopes

Professor Adjunto

*Departamento de Química - Setor de Ciências Exatas*

Universidade Federal do Paraná (UFPR)

*Curitiba - Paraná*

*LinkedIn  |
ORCID  | Lattes
*
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[Ifeffit] weak scattering from second-nearest neighbors for single atom catalysts

2024-02-08 Thread Qiang 
Hi everyone,

I would like to have a discussion about the common EXAFS for single atom 
catalysts. It is usually observed that there is only one strong peak around 
1.5A in EXAFS, and it is attributed to the nearest neighbors of O or N. Take an 
example of Pt1/CeO2 catalyst. Pt single atom is coordinated with a few oxygens, 
i.e., PtOx. These oxygens constitute the first shell of Pt. It is supposed that 
these O should also attach to the metal element of the support (Ce here). So 
there is also Pt-O-Ce structure. Why it doesnot have strong scattering peak in 
EXAFS? Is it that because the Pt-O-Ce formed is not ordered, or it is actually 
not a bond just some weak contact?

Thank you very much.

Qiang

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