NMR-STUDY OF THE FERROELASTIC-TO-PARAELASTIC PROTONIC SUPERIONIC TRANSITION IN RB3H(SEO4)2

被引：44

作者：

ABRAMIC, D ^{[1
]}

DOLINSEK, J ^{[1
]}

BLINC, R ^{[1
]}

SHUVALOV, LA ^{[1
]}

机构：

[1] ACAD SCI USSR,INST CRYSTALLOG,MOSCOW V-71,USSR

来源：

PHYSICAL REVIEW B | 1990年 / 42卷 / 01期

关键词：

D O I：

10.1103/PhysRevB.42.442

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The drastic changes in the angular dependence of the Rb87 quadrupole-perturbed 1/2 - 1) / 2 NMR spectra on going through Tc=446 K as well as the temperature dependence of the proton spectra demonstrate that the structural phase transition in Rb3H(SeO4)2 involves a breakup of the SeO4-H...SeO4 hydrogen-bonded dimers and the formation of a dynamic two-dimensional H-bonded network formed by reorienting HSeO4 groups in the a-b plane. The temperature dependence of the order parameter, which measures the difference in the probabilities of H-bond formation in the three possible directions of the triangular lattice, has been deduced from the NMR spectra. The spin-lattice relaxation time measurements further allowed for a determination of the activation energy Ea=0.45 0.05 eV for defect formation, leading to proton conductivity even below Tc. © 1990 The American Physical Society.

引用

页码：442 / 446

页数：5