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Ferroelectric, piezoelectric and electrostrictive properties of Sn 4+ ‐modified Ba 0.7 Ca 0.3 TiO 3 lead‐free electroceramics
Author(s) -
Baraskar Bharat G.,
Kambale Rahul C.,
James Ajit R.,
Mahesh Manepalli L.,
Ramana Chintalapalle V.,
Kolekar Yessappa D.
Publication year - 2017
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.15073
Subject(s) - electrostriction , ferroelectricity , materials science , tetragonal crystal system , dielectric , curie temperature , condensed matter physics , analytical chemistry (journal) , piezoelectricity , mineralogy , orthorhombic crystal system , electric field , crystal structure , crystallography , chemistry , composite material , ferromagnetism , physics , optoelectronics , chromatography , quantum mechanics
Lead‐free Ba 0.7 Ca 0.3 Ti 1− x Sn x O 3 ( x =0.00, 0.025, 0.050, 0.075, and 0.1, abbreviated as BCST) electroceramic system was prepared by the solid‐state reaction method and its ferroelectric, piezoelectric, and electrostrictive properties were investigated. X‐ray diffraction shows that the compositions with x ≤0.05 exhibit a tetragonal crystal structure having P4mm symmetry; while the compositions x =0.075 and 0.1 exhibit a mixed P4mm+Amm2 phase coexistence of tetragonal and orthorhombic and P4mm+Pm3 ¯m pseudo‐cubic lattice symmetries, respectively, at room temperature. The dense microstructure having relative density ~90%‐92% and average grain size in the range ~2.36 μm to 8.56 μm was observed for BCST ceramics. Temperature‐dependent dielectric measurements support the presence of phase coexistence and show the decrease in Curie temperature ( T C ) with Sn 4+ substitution. The dielectric loss (tan δ) values in the temperature range (−100°C to 150°C) was observed to be <4%, for all BCST ceramics. The BCST compositions exhibit typical polarization‐electric field (P‐E) hysteresis and electric field induced strain (S‐E) butterfly loop, which confirms the ferroelectric and piezoelectric character. The compositions x =0.025, 0.05 and 0.075 show the peaking behavior of displacement current density ( J → ) to an applied electric field ( E → ) (J‐E) which implies the saturation state of polarization. The maximum electrostrictive coefficient ( Q 33 ) value of 0.0667 m 4 /C 2 was observed for x =0.075 and it is higher than some of the significant lead‐based electrostrictive materials. The compositions x =0.05 and 0.075 exhibit the notable electrostrictive properties that may be useful for piezoelectric Ac device applications. The observed results are discussed and correlated with the structure‐property‐composition.