TY - JOUR
T1 - Pressure induced disordering of vacancies in RNi2 compounds
AU - Lindbaum, A.
AU - Heathman, S.
AU - Gratz, E.
PY - 2002/5
Y1 - 2002/5
N2 - As known from earlier investigations, most of the RNi2 compounds (R. . .rare earth element) do not crystallize in the cubic Laves phase structure (C15), but in a superstructure of C15 with ordered vacancies at the R sites. In the present work high pressure X-ray diffraction experiments on selected RNi2 compounds (R = Tb, Sm, Gd and Y) are presented, showing that pressures of about 8-15 GPa lead to a disordering of the vacancies in all of them. Furthermore the studies show that the pressure-induced order-disorder transition is closely related to the earlier observed disordering of the vacancies at high temperatures between 430 K (TbNi2) and 740 K (YNi2), and that there is a pronounced variation of the transition pressures and temperatures among the investigated compounds.
AB - As known from earlier investigations, most of the RNi2 compounds (R. . .rare earth element) do not crystallize in the cubic Laves phase structure (C15), but in a superstructure of C15 with ordered vacancies at the R sites. In the present work high pressure X-ray diffraction experiments on selected RNi2 compounds (R = Tb, Sm, Gd and Y) are presented, showing that pressures of about 8-15 GPa lead to a disordering of the vacancies in all of them. Furthermore the studies show that the pressure-induced order-disorder transition is closely related to the earlier observed disordering of the vacancies at high temperatures between 430 K (TbNi2) and 740 K (YNi2), and that there is a pronounced variation of the transition pressures and temperatures among the investigated compounds.
KW - Diamond anvil cell
KW - Order-disorder transition
KW - Superstructure
KW - Synchrotron radiation
KW - Vacancies
UR - http://www.scopus.com/inward/record.url?scp=0348001996&partnerID=8YFLogxK
U2 - 10.1080/08957950212805
DO - 10.1080/08957950212805
M3 - Article
AN - SCOPUS:0348001996
VL - 22
SP - 411
EP - 414
JO - High Pressure Research
JF - High Pressure Research
SN - 0895-7959
IS - 2
ER -