Glassy behavior study of dysprosium doped barium zirconium titanate relaxor ferroelectric

Abstract

Abstract:We report the glassy behavior of dysprosium doped barium zirconium titanate single phase perovskite ceramics with general formula Ba 1x Dy 2x/3 Zr 0.25 Ti 0.75 O 3 prepared by solid-state reaction method. Temperature and frequency dependent dielectric studies of the ceramics reveal relaxor behavior. A non-Debye relaxation, which is analogous to the magnetic relaxation in spin-glass system, is observed clearly around temperature of dielectric permittivity maximum (T m ). Frequency dependence of T m governed by production of polar nano-regions is analyzed using Debye relation, Vogel-Fulcher (V-F) relation and power law. A clear change in dynamic behavior is observed by power parameter which is related to growth of interactions between polar nano-regions with different composition. Various parameters like activation energy for relaxation, freezing temperature, relaxation frequency, etc., are determined after non-linear curve fitting. Temperature dependence of dielectric constant at temperatures much higher and lower than T m is analyzed by two exponential functions, which gives an idea about the production of polar clusters at high temperature and distribution of freezing temperatures at lower temperature. Various other associated parameters are calculated by non-linear curve fitting and their significance has been explained.

Lattice strain accommodation and absence of pre-transition phases in Ni50Mn25+x In25−x

“…The presence of impurities tends to curtail the long range order of the strain vector leading to a frozen disordered ferroelastic phase. This phase is akin to cluster glassy phase in impurity doped magnetic materials [1,2] or relaxor ferroelectrics [3][4][5]. Several reports depicting the existence of strain glass phase have been reported in the literature [6,7].…”

Dielectric behaviors and relaxor characteristics in Bi0.5Na0.5TiO3-BaTiO3 ceramics

“…39 The broad distribution of freezing temperatures was similar with the results reported for other relaxor ceramics such as Ba-doped PYT and Dy-doped barium zirconium titanate. 42,43 In Table 1, another notable striking is the low E aÀH value and the high T f ÀH value in x ¼ 0:4 sample compared with values for the other x compositions. This result is a coincidence with the prominent dielectric thermal hysteresis responses for x ¼ 0:4 composition.…”

Lattice strain accommodation and absence of pre-transition phases in Ni$_{50}$Mn$_{25+x}$In$_{25-x}$

“…The presence of impurities tends to curtail the long range order of the strain vector leading to a frozen disordered ferroelastic phase. This phase is akin to cluster glassy phase in impurity doped magnetic materials [1,2] or relaxor ferroelectrics [3,4,5]. Several reports depicting the existence of strain glass phase have been reported in the literature [6,7].…”