Synthesis, phase confirmation and electrical properties of (1 ? x)KNNS?xBNZSH lead-free ceramics
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Date
2022-02-02T00:00:00
Authors
Kumar, Amit
Kumari, Sapna
Kumar, V.
Kumar, Prashant
Thakur, Vikas N.
Kumar, Ashok
Goyal, P.K.
Arya, Anil
Sharma, A.L.
Journal Title
Journal ISSN
Volume Title
Publisher
Springer
Abstract
In the present work, lead-free piezoelectric ceramics (Rx)(K0.5Na0.5)(Nb0.96Sb0.04O3)?x(Bi0.5Na0.5)(Zr0.8Sn0.1Hf0.1)O3 [abb. as (Rx)KNNS?xBNZSH, 0 ? x ? 0.04] were prepared via solid-state sintering technique. The thermal behavior of mixed powders has been investigated for x = 0, 0.02, and 0.04 using TGA-DSC analysis to estimate the calcination temperature. The structural, morphological, dielectric, ferroelectric and piezoelectric properties are analyzed through the appropriate characterization techniques. The X-ray diffraction (XRD) patterns demonstrate a pure perovskite phase structure for all the sintered samples. Further, the coexistence of rhombohedral to orthorhombic (R-O) phase is observed in ceramic sample with x = 0.02. The morphology of all the sintered samples exhibits an inhomogeneous, dense microstructure with the rectangular grain, while for x = 0.02, a relatively homogeneous distribution of grains is observed. BNZSH doping decreases the average grain size from 2.22 to 0.33�?m for x = 0 to x = 0.04, respectively. Owing to the presence of multiple-phase coexistence as well as the improved microstructure and enhanced dielectric properties (dielectric constant ?r = 1080, ?max = 5301; Curie temperature - TC ~ 317��C; dielectric loss - tan? ~ 6%) the ceramics with x = 0.02 has been found to have a large piezoelectric coefficient (d33) of ~180 pC/N, remnant polarization (Pr) ~ 16.7 �C/cm2 and coercive field (Ec) ~ 10.7�kV/cm. We believe it will expand the range of applications for KNN-based ceramics. � 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
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Keywords
Morphology, Perovskite, Phase structure, Piezoelectric ceramics, Piezoelectricity, Sintering, Calcination temperature, Dielectrics property, Lead free ceramics, Lead-free piezoelectric ceramic, Mixed powder, Sintered samples, Solid state sintering, Synthesis phase, Tga-dsc, Thermal behaviours, Dielectric losses