Vanishing of the phase transitions and quantum effects in K2SeO4 at high pressure

G. A. SAMARA; N. E. MASSA; F. G. ULLMAN

FERROELECTRICS

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 1981 vol. 36 p. 335 - 338

0015-0193

The effects of pressure on the dielectric properties and phase transition in K2SeO4 were investigated. The incommensuratetocommensurate ferroelectric transition vanishes at 0.73 GPa, and the paraelectric to incommensurate transition is expected to vanish at ∼ 1.13 GPa. These large pressure effects can be understood in terms of the delicate balance between Coulomb and shortrange interactions. The results show the increased influence of quantum effects on approaching the displacive limit (i.e. Tc = O K), and they confirm the existence of a γ = 2 regime in the temperature dependence of the susceptibility, as predicted by recent theories.