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Processing of 0.55(Ba 0.9 Ca 0.1 )TiO 3 ‐0.45Ba(Sn 0.2 Ti 0.8 )O 3 lead‐free ceramics with high piezoelectricity
Author(s) -
Bijalwan Vijay,
Tofel Pavel,
Spotz Zdeněk,
Částková Klára,
Sobola Dinara,
Erhart Jiří,
Maca Karel
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.17090
Subject(s) - materials science , analytical chemistry (journal) , calcination , orthorhombic crystal system , mineralogy , tetragonal crystal system , ceramic , phase boundary , raman spectroscopy , piezoelectricity , phase (matter) , crystallography , crystal structure , composite material , chemistry , optics , physics , biochemistry , organic chemistry , chromatography , catalysis
Abstract We report a large piezoelectric constant ( d 33 ), 720 pC/N and converse piezoelectric constant ( d 33 * ), 2215 pm/V for 0.55(Ba 0.9 Ca 0.1 )TiO 3 ‐0.45Ba(Sn 0.2 Ti 0.8 )O 3 ceramics; the biggest value achieved for lead‐free piezoceramics so far. The ceramic powders were calcined between 1050°C‐1350°C and sintered at 1480°C. The best properties were obtained at a calcination temperature (CT) of 1350°C. The fitting combination of processing and microstructural parameters for example, initial powder particle size >2 µm, ceramics density ~95%, and grain size ~40 µm led to a formation of orthorhombic‐tetragonal‐pseudo‐cubic (O‐T‐PC) mixed phase boundary near room temperature, supported by Raman spectra, pointed to the extremely high piezoelectric activity. These conditions significantly increase piezoelectric constants, together with high relative permittivity ( ε r ) >5000 and a low loss tangent (tan δ ) of 0.029. In addition, the d 33 value stabilizes in the range of 400‐500 pC/N for all samples calcined between 1050°C and 1250°C. The results entail that the (Ba,Ca)(Sn,Ti)O 3 ceramics are strong contenders to be a substitute for lead‐based materials for room temperature applications.