作者:S. Rı́os、M. Quilichini、K. Knorr、G. André
DOI:10.1016/s0921-4526(99)00091-5
日期:1999.6
This paper reports on the first structural results of a (P, T) phase diagram study of the antiferroelectric (T-c = 353 K) TlD2PO4 by means of neutron powder diffraction. The temperature range studied was from room temperature to 400 K, and up to 8 kbar in pressure. At T > T-c and pressures above 3 kbar a new phase transition takes place, which seems to have the same features of the orthorhombic to monoclinic transition observed in TlH2PO4 at room pressure when decreasing temperature below 357 K. The pressure-induced phase transition in TlD2PO4 is thus compared to the one observed in the homologue TlH2PO4. For T < T-c the same high-pressure monoclinic phase is also observed with an intermediate phase which is likely to correspond to the room pressure high-temperature prototype phase (Pbcn). (C) 1999 Elsevier Science B.V. All rights reserved.