Improvement of the phase diagram for the pseudobinary PbNb2O6–BaNb2O6 system

Characteristics of phase transitions of lead barium niobate compositions around the morphotropic phase boundary were investigated. Using structural characterizations, it was found that the morphotropic phase boundary extends toward a wide composition range, in which both tetragonal (4mm) and orthorhombic (m2m) tungsten bronze phases coexist. In addition, on heating, two phase transitions were observed for all the studied compositions. First, the fraction with m2m symmetry phase transforms into the 4mm symmetry one and, second, the 4mm symmetry phase, which represents the whole material, transforms into the paraelectric phase (4/mmm symmetry). The phase transition temperatures were determined from dielectric characterizations. These results helped to improve the phase diagram of the pseudobinary PbNb2O6–BaNb2O6 system around the morphotropic phase boundary region.

[1]  J. Eiras,et al.  Anisotropic properties in textured lead barium niobate compositions around the morphotropic phase boundary , 2009 .

[2]  R. Pérez,et al.  Extrinsic response anisotropy in ferroelectric perovskite polycrystals , 2007 .

[3]  R. Pérez,et al.  Extrinsic effects in twinned ferroelectric polycrystals , 2007 .

[4]  J. Eiras,et al.  Raman scattering investigation on the phase evolution of ferroelectric lead barium niobate , 2001 .

[5]  Yu-huan Xu,et al.  3 – Perovskite-type ferroelectrics: part I , 1991 .

[6]  Yuhuan Xu,et al.  Ferroelectric Materials and Their Applications , 2023, Japanese Journal of Applied Physics.

[7]  C. Randall,et al.  Polarization mechanisms of morphotropic phase boundary lead barium niobate (PBN) compositions , 1990 .

[8]  G. Burns,et al.  Studies on annealing and quenching of strontium barium niobate (sbn) single crystals: A-site cation ordering-disordering effect , 1989 .

[9]  Huanchu Chen,et al.  Dielectric and piezoelectric properties of pb1-xbaxnb2o6 ferroelectric tungsten bronze crystals , 1987 .

[10]  A. M. Glass,et al.  Principles and Applications of Ferroelectrics and Related Materials , 1977 .

[11]  G. Shirane,et al.  X‐ray dielectric, and optical study of ferroelectric lead metatantalate and related compounds , 1960 .

[12]  M. Francombe The relation between structure and ferroelectricity in lead barium and barium strontium niobates , 1960 .

[13]  E. Subbarao Nonstoichiometric PbNb2O6‐Type Solid Solutions , 1959 .