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Electrical Properties of Lead‐Free Na 1/2 Bi 1/2 TiO 3 Relaxor Ferroelectric Ceramics Doped with Hafnium or Zirconium
Author(s) -
Kırsever Derya,
Yılmaz Hüseyin
Publication year - 2015
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.13550
Subject(s) - materials science , zirconium , hafnium , electrostriction , ceramic , doping , ferroelectricity , dielectric , grain growth , analytical chemistry (journal) , grain size , mineralogy , composite material , metallurgy , optoelectronics , piezoelectricity , chemistry , chromatography
Ferroelectric (Na 1/2 Bi 1/2 )TiO 3 and its various solid solutions have been drawing special attention as a new candidate for their lead‐based counterparts. In this study, therefore, hafnium‐ or zirconium‐doped grain‐oriented (Na 1/2 Bi 1/2 )TiO 3 ceramics with <001> pc orientation were fabricated by templated grain growth method using anisotropically shaped SrTiO 3 template particles. These molten salt synthesized SrTiO 3 platelets were tape cast with calcined (Na 1/2 Bi 1/2 )TiO 3 powders, and then sintered at 1200°C for 6 h. Texture fractions up to 70% have been obtained. Unipolar strains up to >0.25% were measured. Doped ceramics showed a “relaxor‐like” ferroelectric behavior. A broad dielectric peak with a slim hysteresis loop was present for hafnium‐ or zirconium‐doped samples. Electrostrictive coefficient of hafnium‐doped (Na 1/2 Bi 1/2 )TiO 3 ceramics were found to be 0.032 m 4 /C 2 , which is much larger than that of PMN ‐based electrostrictive materials. Electromechanical properties of hafnium‐ and zirconium‐doped (Na 1/2 Bi 1/2 )TiO 3 ceramics under electric bias were studied as well.