Some articles do not clearly detail the peaks positions of the omega phase.
There tends to be a relationship between Omega and Beta; if you can find beta peaks, extract the unit cell A from this; the omega unit cell will have the relationship a = sqrt(2)*A, c = (sqrt(3)/2)*A. I've seen this relationship hold up quite well in my own work.
Review on ω phase in body-centered cubic metals and alloys (Review)
Ping, D
Acta Metallurgica Sinica (English Letters)
Volume 27, Issue 1, February 2014, Pages 1-11
Omega phase can also have a hexagonal structure. Please see below the crystallographic data:
Omega-Ti , S.G.: P6/mmm (191)
a: 4.646(4)
c: 2.820(2)
C: 0.6070
d-spacing /A intensity plane
2.819 50 0 0 1
2.307 100 1 0 1
1.779 50 1 1 1
1.632 75 2 0 1
1.409 35 0 0 2
1.339 75 3 0 0
1.204 80 1 1 2
1.162 5 2 2 0
1.049 35 3 1 1
0.966 35 3 0 2
0.941 5 0 0 3
0.916 5 1 0 3
0.892 5 2 2 2
0.879 35 2 3 1
0.798 10 2 1 3
0.675 10 1 1 4
Ref: Ming, L.-c., Manghnani, M., Katahara, K., Acta Metall., 29 479 (1981)
Very good! This is exactly that I was searching! Thank you very much Mr. Siemers. Kind regards.
Dear Diego,
the data I sent you is also published in the PDF2 database (entry 510631). If you perform XRD phase analyses, you should consider buying something similar as otherwise peak identification is difficult. In case you work with metals only, PDF4 is not much better compared to PDF2.
Hickmann et al and others also report a cubic omega-phase which I personally never observed (and omega-phase to my knowledge is the metastable phase transforming to alpha-Ti if heated), but that might be due to the alloys we analyse. I checked the PDF2 database but there is no cubic omega-phase. Nevertheless, it might be worth checking the literature as it is unclear which omega-phase you have.
Anyway, good luck with your analyses,
Carsten
- Badges
- Science method
- Similar topics
- Methodology
- Crystallography
- X-ray Diffraction