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CaTiO 3 induced ferroelectric phase coexistence and low temperature dielectric relaxation in BaTiO 3 –BaZrO 3 ceramics
Author(s) -
Sutapun Manoon,
Charoonsuk Thitirat,
Kolodiazhnyi Taras,
Vittayakorn Naratip
Publication year - 2018
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.15351
Subject(s) - materials science , dielectric , curie temperature , ferroelectricity , tetragonal crystal system , orthorhombic crystal system , temperature coefficient , rietveld refinement , analytical chemistry (journal) , phase transition , phase (matter) , dielectric loss , relaxation (psychology) , transition temperature , activation energy , nuclear magnetic resonance , condensed matter physics , mineralogy , crystallography , crystal structure , chemistry , composite material , ferromagnetism , superconductivity , psychology , social psychology , physics , optoelectronics , organic chemistry , chromatography
The series of 0.86BaTiO 3 –(0.14− x )BaZrO 3 – x CaTiO 3 (abbreviated as BT – BZ – x CT ) ceramics with 0.03 ≤ x ≤ 0.11 were studied to obtain high piezoelectric properties. Rietveld refinement analysis indicated that the BT – BZ – CT compositions follow a gradual rhombohedral ( R ) → orthorhombic ( O ) + R → O + tetragonal ( T ) → T phase transformation with increasing x . Clear evidence of the series of ferroelectric phase transitions was also found in the dielectric results. The R ‐ O and O ‐ T transition temperature shifted close to ambient temperature, while the Curie temperature slightly increased with increasing x . In addition to the dielectric loss peaks associated with the structural phase transitions, a broad low‐temperature dielectric loss peak was detected in the R phase at T = 90‐150 K. This dielectric relaxation was attributed to the domain wall freezing and fits well to the Vogel‐Fulcher model with activation energy E a ≈ 60‐300 meV and freezing temperature T VF ≈ 75‐140 K. High piezoelectric strain coefficient ( d 33 *) of about 1030 pm/V at 10 kV was achieved at x = 0.07, and a high Curie temperature ( T C ) was maintained at about 375 K.