PHASE-TRANSITION IN PB5AL3F19

被引：3

作者：

ANDRIAMAMPIANINA, V ^{[1
]}

RAVEZ, J ^{[1
]}

SIMON, A ^{[1
]}

ABRAHAMS, SC ^{[1
]}

机构：

[1] UNIV TUBINGEN,INST KRISTALLOG,W-7400 TUBINGEN 1,GERMANY

来源：

PHASE TRANSITIONS | 1991年 / 33卷 / 1-4期

关键词：

D O I：

10.1080/01411599108207715

中图分类号：

O7 [晶体学];

学科分类号：

0702 ; 070205 ; 0703 ; 080501 ;

摘要：

A study of the PbF2-AlF3system has resulted in a new material Pb5Al3F19with a tetragonal structure at room temperature closely related to that of Pb5Cr3F19. A phase transition in Pb5Al3F19has been detected by means of X-ray diffraction, calorimetric and dielectric measurements. The coexistence of the high and low-temperature Pb5Al3F19phases over the range 270 to 300 K and the abrupt 0.7% increase in the a-axis and 1.5% decrease in the c-axis, on heating through the phase transition, are characteristic of a first-order phase change. The increase in symmetry from point group 4 below to point group 4#x002F;m above the phase transition is consistent with a ferroelectric to paraelectric transition, as found previously in Pb5Cr3F19. © 1991, Taylor & Francis Group, LLC. All rights reserved.

引用

页码：77 / 79

页数：3