Dielectric Properties of (Bi 0.5 K 0.5 )ZrO 3 Modified (K 0.5 Na 0.5 )NbO 3 Ceramics as High-Temperature Ceramic Capacitors

摘要: (1 − x)K0.5Na0.5NbO3-x(Bi0.5K0.5)ZrO3 [abbreviated as x)KNN-xBKZ, 0 ≤ x 0.08] lead-free ceramics have been fabricated by a solid-state processing route. Based on the x-ray diffraction data and temperature-dependent dielectric characteristics, an orthorhombic phase for 0.03 single rhombohedral one ≥ 0.05 at room temperature were determined. The cell volume firstly increases, then decreases finally increases with increasing BKZ, depending ionic size crystallographic structure. For sample of = 0.05, temperature-stable high permittivity (~ 1736 ± 15%) along low loss tangent (≤ 5%) is recorded from 158°C to 407°C. In addition, activation energies relaxation dc conductivity temperatures characterized impedance spectroscopy. A combined effect lattice distortion oxygen vacancies magnitude was discussed.