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High‐pressure structural investigation on lead‐free piezoelectric 0.5 Ba ( Ti 0.8 Zr 0.2 ) O 3 ‐ 0.5( Ba 0.7 Ca 0.3 ) TiO 3
Author(s) -
Mondal Anshuman,
Saha Pinku,
Ghosh Bishnupada,
Sahu Mrinmay,
Mukherjee Goutam Dev,
Ranjan Rajeev,
Brajesh Kumar
Publication year - 2020
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.17167
Subject(s) - ferroelectricity , materials science , raman spectroscopy , dielectric , tetragonal crystal system , orthorhombic crystal system , phase boundary , rietveld refinement , phase transition , phase (matter) , crystallography , piezoelectricity , crystal structure , condensed matter physics , chemistry , composite material , optics , physics , optoelectronics , organic chemistry
The solid solution 0.5 Ba ( Ti 0.8 Zr 0.2 ) O 3 − 0.5( Ba 0.7 Ca 0.3 ) T iO 3 (BCZT) has become a promising member of the lead‐free piezoelectric materials because of its exceptionally high piezoelectric properties. In this study, we focus on studying pressure‐dependent Raman spectroscopy, powder x‐ray diffraction, and dielectric constant measurements on BCZT. The data show several structural transitions are present, where the system from ambient mixed phase (tetragonal P4mm + orthorhombic Amm2 ) transforms into single phase ( P4mm ) at 0.3 GPa, then converts into cubic phase ( Pm3m ) at 4.8 GPa followed by another possible structural re‐ordering around 10 GPa. Although there have been a lot of unanimity with the ambient crystallographic state of BCZT, our analysis justifies the presence of an intermediate orthorhombic phase in the Morphological Phase Boundary (MPB) of BCZT phase diagram. The transformation tetragonal to cubic is indicated by the Raman mode softening, unit cell volume change, and the ( Ti/Zr ) O 6 octahedra distortion, which coincides with the well‐known ferroelectric‐paraelectric transition of the system. The sudden drop in the dielectric constant value at 4.7 GPa also confirms the loss of ferroelectric nature of the BCZT ceramic.