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Ferroelectric and magnetic properties in (1− x )BiFeO 3 – x (0.5CaTiO 3 –0.5SmFeO 3 ) ceramics
Author(s) -
Liu Juan,
Liu Xiao Qiang,
Chen Xiang Ming
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.14952
Subject(s) - ferroelectricity , materials science , dielectric , multiferroics , orthorhombic crystal system , phase boundary , atmospheric temperature range , raman spectroscopy , ceramic , analytical chemistry (journal) , dielectric loss , relaxation (psychology) , condensed matter physics , phase (matter) , nuclear magnetic resonance , crystal structure , crystallography , chemistry , thermodynamics , optics , composite material , psychology , social psychology , physics , optoelectronics , organic chemistry , chromatography
Multiferroic ceramics were prepared and characterized in (1− x )BiFeO 3 – x (0.5CaTiO 3 –0.5SmFeO 3 ) system by a standard solid‐state reaction process. The structure evolution was investigated by X‐ray diffraction and Raman spectrum analyses. The refinement results confirmed the different phase assemblages with varying amounts of polar rhombohedral R3c and nonpolar orthorhombic Pbnm as a function of the substitution content. In the compositions range of 0.2≤ x ≤0.5, polar R3c and nonpolar Pbnm coexisted, which was referred to polar‐to‐nonpolar morphotropic phase boundary ( MPB ). According to the dielectric and DSC analysis results, the ceramics with x ≤0.2 changed to diffused ferroelectric, and the ferroelectric properties were enhanced significantly. Two dielectric relaxations were detected in the temperature range of 200‐300 K and 500‐700 K, respectively. The high‐temperature dielectric relaxation was attributed to the grain‐boundary effects. While the low temperature dielectric relaxation obtained in the samples with x =0.3‐0.5 was related to the charge transfer between Fe 2+ and Fe 3+ . The magnetic hysteresis loops measured at different temperature indicated the enhanced magnetic properties in the present ceramics, which could be attributed to the suppressed cycloidal spin magnetic structure by Ti ions. In addition, the rare‐earth Sm spin moments might also affect the magnetic properties at relatively lower temperature.