Phonon dispersion calculations using the Vaks model in antiferroelectric lead zirconate  

作　　者：D.A.Andronikova R.G.Burkovsky A.V.Filimonov A.K.Tagantsev S.B.Vakhrushev 

机构地区：[1]Peter the Great St.Petersburg Polytechnic University,Polytechnicheskaya 29,St.Petersburg 195251,Russia [2]Ioffe Institute,Politekhnicheskaya 26,St.Petersburg 194021,Russia [3]European Synchrotron Radiation Facility,BP 220 F-38043 Grenoble Cedex,France [4]Ceramics Laboratory,Swiss Federal Institute of Technology(EPFL)CH-1015 Lausanne,Switzerland

出　　处：《Journal of Advanced Dielectrics》2015年第2期84-88,共5页先进电介质学报（英文）

摘　　要：The calculations of low-energy phonon dispersion relations in lead zirconate(PZ)have been carried out using the Vaks model.This model takes into account only five low-energy phonon modes and their interactions.It has been shown that this model allows to achieve good agreement not only between calculated and experimental transverse acoustic phonon dispersion but also between their temperature dependences.It has been shown 5-mode system,which describes low-energy phonon dispersion in PZ,is close to unstable state.Even a little change of interaction parameter can lead to lattice instability with nonzero wave vector qcrit.Wave vector qcrit could have any value,including irrational one.In this case,system will undergo an incommensurate phase transition.

关 键 词：Lead zirconate ANTIFERROELECTRICITY incommensurate phase 

分 类 号：O57[理学—粒子物理与原子核物理]