Hi,
I am having problem with indexing of ring diffraction
pattern obtained by Synchrotron radiation NiTi SMA
alloy in no stress and stressed condition.
1.I have calculated 'd' spacing for each ring.
A. For no load condition (austenite-b2 structure)
calculated 'd(in angstrom)' data is
3.180953934,2.544763147,2.20295878,1.830587683
1.580730311
by STD. hkl reflection d spacing for austenite Ni-Ti
is
(1 0 0) 3.00926
(1 1 0) 2.12787
(1 1 1) 1.7374
(2 0 0) 1.50463
(2 1 0) 1.34578
I can understand ordered b2 structure of austenite
acts as simple cubic in diffraction behavior.I can
index the data easily, but 2.544763147 this calculated
'd' i couldn't fit with STD data.
Also in stressed condition i am getting first
reflection 'd'spacing claculated is 4.266783322 and by
STD what i have is (0 1 1) 3.07927.which is not at all
matching.
B.For stressed condition (martenisite- b19'
monoclinic)of NiTi sample calculated 'd(in
angstrom)'from diffarction ring data is
4.266783322,3.224330579,2.556226044,2.25191342,1.818853147,1.585145759
by STD. hkl reflection d spacing for martensite Ni-Ti
is
(0 1 1) 3.07927,(1 0 0) 2.86543,(-1 1 0)2.52841,(1 0
1)2.35966,(1 1 0) 2.34098,(0 2 0) 2.29035,(-1 1
1)2.16035
(0 0 2) 2.07962,(1 1 1) 2.04004,(1 2 1) 2.00628,(0 1
2)1.89361,(-1 2 0)1.86867,(1 0 2) 1.68307,(1 2 0)
1.71884
(-1 2 1)1.70454,(-1 1 2)1.60613,(1 2 1) 1.58854
WHEN I SEARCHED FOR CRYSTALLOGRAPIC DATA FOR NI-TI
intermettalic PHASE, I CAME TO KNOW VARIOUS
INTERMEDIATE PHASES AS Ni3Ti(hexagonal DO24 str) ,
NiTi (cubic) ,
piTi-Ni (hexagonal?) ,NiTi2(cubic)
have anyone gone through indexing diffraction pattern
for SMA NiTi alloy ?where I will find standard d
spacing for various h,k,l reflection in in above all
phase structures.?
Any help would be greatly appreciated.
Chandra
University of central florida.
2.
__________________________________________________
Do You Yahoo!?
Get personalized email addresses from Yahoo! Mail
http://personal.mail.yahoo.com/
