The influences of Cs+ substitution and direct doping on the phase evolution, microstructure and electrical properties of KNNT ceramics. Issue 1 (3rd December 2021)

• Record Type: Journal Article
• Authors: Yotthuan, Surirat; Udeye, Thanya; Vittayakorn, Naratip; Eitssayeam, Sukum; Pulphol, Phieraya; Bongkarn, Theerachai
• Is Part Of: Ferroelectrics. Volume 586:Issue 1(2022)
• Page Start: 133
• Page End: 146
• Publication Date: 2021-12-03
• Subjects: KNNT -- phase evolution -- Rietveld refinement -- solid-state combustion technique; Ferroelectricity -- Periodicals; Ferroelectric crystals -- Periodicals; 537
• DOI: 10.1080/00150193.2021.2014266
• Languages: English
• ISSNs: 0015-0193

Abstract

Abstract: The effects of Cs + substitution and direct doping in (K0.5 Na0.5 )(Nb0.7 Ta0.3 )O3 (KNNT) ceramics, on the crystal structure, microstructure and electrical properties were investigated. Both the KNNT with Cs + substitution (K0.5-x Csx NNT) and addition (KNNT-xCs) (x = 0, 0.01, 0.02, 0.03 and 0.04 mol%) were synthesized by the solid-state combustion technique using glycine as fuel. All samples were sintered at 1130–1150 °C for 4 h. The x-ray diffraction (XRD) analysis for the ceramics revealed the presence of orthorhombic ( O ) and tetragonal ( T ) phases in all samples. Increasing both the Cs + substitution and doping amounts, enhanced the content of orthorhombic phase, as verified by the Rietveld refinement technique. It was found that Cs + doping, either substitutional or additional, strongly decreased their density, dielectric and ferroelectric properties. The undoped KNNT ceramic exhibited well-saturated P - E hysteresis loop. With Cs + doping, the samples became unsaturated and a leakage current was produced. The KNNT-xCs ceramics demonstrated higher density and dielectric properties than the K0.5-x Csx NNT ceramics.