Spherical random-bond–random-field model of relaxor ferroelectrics

Bias-field effect on the temperature anomalies of dielectric permittivity inPbMg1∕3Nb2∕3

“…It is important that coupling between P and Q changes the FC line and, in particular, there appears a critical field, 27 below which there are no phase transitions in agreement with experiment.…”

“…A widely accepted model of relaxors 27 considers dipoles under the action of random bonds and in random fields, which were introduced into the discussion of relaxor behavior previously. 32,33 In the present study, we concentrate on the bias-field dependence of the diffuse peak.…”

“…The Landau coefficient ␣ is assumed to depend on T in the manner which has been described by Potts-type model computations of PMN ͑Ref. 36͒ as well as by the SRBRF model and experiment: 24,27 it decreases linearly with decreasing temperature and saturates at low temperatures without crossing zero. Correspondingly, due to random fields and random bonds, the correlation length increases as temperature decreases and, then, saturates at low temperatures.…”

Strain Mechanisms in Lead-Free Ferroelectrics for Actuators

“…However, so far no general agreement in their microscopic picture has been achieved. The most widely accepted attempts capable of describing only some of their features are known as the diffuse phase transition model 76,77 , superparaelectric model 53 , glassy state model [85][86][87] , random fields model [88][89][90][91] , spherical random bond-random field model [92][93][94][95][96] , and breathing model. 97,98 These models can be categorized according to two microscopic views.…”

Anharmonic atomic vibrations in the relaxor ferroelectric Pb(Mg1/3Nb2/3)OYamanaka1, Ahart2, Nakamoto3 et al. 2012Phys. Rev. B8050View full textAdd to dashboardCite

“…In addition, their high permittivity and high piezoelectric constants make them suitable for applications in devices for sonar or medical imaging [1]. While extensive theoretical [3][4][5][6][7] and experimental studies [1][2][3][7][8][9][10][11][12] have advanced the fundamental understanding of relaxor behavior, their properties are still poorly understood. The difficulties stem from the complexity of these materials, which have a high degree of compositional, structural and polar disorder.…”