X-ray diffraction and Raman study of DL-alanine at high pressure: revision of phase transitions.
The effect of pressure on DL-alanine has been studied by X-ray powder diffraction (up to 8.3 GPa), single-crystal X-ray diffraction and Raman spectroscopy (up to ~6 GPa). No structural phase transitions have been observed. At ~1.5-2 GPa, cell parameters b and c become accidentally equal to each other, but the space-group symmetry does not change. There is no phase transition between 1.7 and 2.3 GPa, contrary to what has been reported earlier [Belo et al. (2010). Vibr. Spectrosc. 54, 107-111]. The presence of the second phase transition, which was claimed to appear within the pressure range from 6.0 to 7.3 GPa (Belo et al., 2010), is also argued. The changes in the Raman spectra have been shown to be continuous in all the pressure ranges studied.
Institute of Solid State Chemistry and Mechanochemistry SB RAS, Kutateladze 18, Novosibirsk 630128, Russian Federation. n.tumanov@gmail.com
Nikolay A
NA
Tumanov
Elena V
EV
Boldyreva
D000409:Alanine / Q000737:chemistry*; D018360:Crystallography, X-Ray; D044367:Phase Transition; D055585:Physical Phenomena; D013059:Spectrum Analysis, Raman / Q000379:methods*; D014961:X-Ray Diffraction / Q000379:methods*
D000409:Alanine