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Structure evolution, dielectric, and conductivity behavior of (K0.5Na0.5)NbO3-Bi(Zn2/3Nb1/3)O3 ceramics
- Source :
- Journal of Advanced Ceramics, Vol 10, Iss 4, Pp 809-819 (2021)
- Publication Year :
- 2021
- Publisher :
- Tsinghua University Press, 2021.
-
Abstract
- (1−x)K0.5Na0.5NbO3−xBi(Zn2/3Nb1/3)O3 ((1−x)KNN−xBZN, x = 0.010, 0.015, 0.020, 0.025, and 0.030) lead-free ceramics were fabricated via a traditional solid-state method. The crystal structure, microstructure, dielectric, and conductivity behavior of this system were studied. Combined with X-ray diffraction (XRD) patterns, Rietveld refinement, and dielectric spectroscopy, an orthorhombic phase was determined for x = 0.010, an orthorhombic-tetragonal mixed phase was identified for x = 0.015, and a rhombohedral symmetry appears in 0.020 ⩽ x ⩽ 0.030. Both 0.98KNN−0.02BZN and 0.975KNN−0.025BZN ceramics exhibit stable permittivity and low dielectric loss tangent (tanδ) in wide temperature ranges owing to the combination of rhombohedral-tetragonal step-like feature and the diffuse phase transition from tetragonal to cubic. The activation energies of dielectric relaxation and conductivity behavior at high temperatures initially decrease slightly, then drop sharply, and finally decline slowly, which could be attributed to microstructure morphologies and the concentration of oxygen vacancies.
- Subjects :
- 010302 applied physics
Permittivity
crystal structure
Materials science
Rietveld refinement
ceramic
Analytical chemistry
Clay industries. Ceramics. Glass
02 engineering and technology
Dielectric
021001 nanoscience & nanotechnology
Microstructure
01 natural sciences
oxygen vacancies
Electronic, Optical and Magnetic Materials
Dielectric spectroscopy
TP785-869
Tetragonal crystal system
0103 physical sciences
Ceramics and Composites
Orthorhombic crystal system
Dielectric loss
0210 nano-technology
dielectric spectroscopy
Subjects
Details
- ISSN :
- 22278508 and 22264108
- Volume :
- 10
- Database :
- OpenAIRE
- Journal :
- Journal of Advanced Ceramics
- Accession number :
- edsair.doi.dedup.....bd1279710f6ee1e89773748ee217f8de