Dwivedi S, Pareek T, Kumar S. Structure, dielectric, and piezoelectric properties of K0.5Na0.5NbO3-based lead-free ceramics.
RSC Adv 2018;
8:24286-24296. [PMID:
35539216 PMCID:
PMC9082108 DOI:
10.1039/c8ra04038a]
[Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 06/29/2018] [Indexed: 11/22/2022] Open
Abstract
Lead-free ceramics based on the (1 − x)K0.5Na0.5NbO3–xBi(Zn0.5Ti0.5)O3 (KNN–BZT) system obtained via the conventional solid-state processing technique were characterized for their crystal structure, microstructure, and electrical properties. Rietveld analysis of X-ray diffraction data confirmed the formation of a stable perovskite phase for Bi(Zn0.5Ti0.5)O3 substitutions up to 30 mol%. The crystal structure was found to transform from orthorhombic Amm2 to cubic Pm3̄m through mixed rhombohedral and tetragonal phases with the increase in Bi(Zn0.5Ti0.5)O3 content. Temperature-dependent dielectric behavior indicated an increase in diffuseness of both orthorhombic to tetragonal and tetragonal to cubic phase transitions as well as a gradual shift towards room temperature. The sample with x ≈ 0.02 exhibited a mixed rhombohedral and orthorhombic phase at room temperature. A high-temperature X-ray diffraction study confirmed the strong temperature dependence of the phase coexistence. The sample with the composition 0.98(K0.5Na0.5NbO3)–0.02(BiZn0.5Ti0.5O3) showed an improved room temperature piezoelectric coefficient d33 = 109 pC/N and a high Curie temperature TC = 383 °C.
Room temperature powder X-ray diffraction patterns of (1 – x)K0.5Na0.5NbO3–xBi(Zn0.5Ti0.5)O3 system.![]()
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