Article,
Investigation of phase transitions in LiK1-x(NH4)(x)SO4 mixed crystal
SOLID STATE COMMUNICATIONS, 109 (8): 507-511 (1999)
DOI: 10.1016/S0038-1098(98)00612-7
Abstract
We present Raman scattering results on LiK1-x(NH4)(x)SO4 mixed crystal
for temperatures between 100 and 300 K. We observed that in this
temperature range the crystal undergoes two different phase transitions,
which we call Bansal and Tomaszewski phase transitions. The introduction
of ammonium ions in the potassium sites increases the C-6(6) --> C-3v(4)
(Bansal) phase transition temperature and decreases the Tomaszewski
phase transition temperature. Finally, the most impressive effect of the
presence of ammonium impurity in the LiKSO4 structure is the decrease in
the temperature hysteresis of Bansal phase transition and the almost
complete destruction of hysteresis in the Tomaszewski phase transition,
leading to a high temperature range of stability of the trigonal phase.
(C) 1999 Elsevier Science Ltd. All rights reserved.
