Open AccessTiO2-(Zn1/3Nb2/3)O2-ZrO2 microwave dielectric ceramics with near-zero temperature coefficient of resonant frequency
Author(s) -
Wang Geng,
Qiuyun Fu,
Lu Zhang
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/892/1/012004
Subject(s) - sintering , materials science , ceramic , temperature coefficient , analytical chemistry (journal) , atmospheric temperature range , dielectric , phase (matter) , mixed oxide , permittivity , stoichiometry , mineralogy , oxide , composite material , metallurgy , chemistry , thermodynamics , physics , optoelectronics , organic chemistry , chromatography
(56.33-x)TiO 2 -x(Zn 1/3 Nb 2/3 )O 2 -43.67ZrO 2 (x = 2.60-37.66) ceramics with 0.5%wt CuO addition were prepared by the mixed metal oxide route. Effects of sintering temperature were investigated on the sintering behavior and microwave dielectric properties of ceramics. For all ceramics with x = 2.60-37.66, the optimal sintering temperature range was determined to be around 1280 °C. XRD analysis showed that the main crystalline phase of ceramics sintered at 1280 °C changed from ZrTiO 4 type at x = 2.60-30.20 to ZrTi 2 O 6 type at x = 30.20-37.66. In addition to the main crystalline phase, trace amounts of secondary phases ZrO 2 and ZnCuTiO 4 were also observed from SEM and EDS analysis for all ceramics. The permittivity decreased with the increasing x in the range of x = 2.60-30.20 and then remained stable at x = 30.20-37.66, corresponding to the density and covalency bond due to the substitution of (Zn 1/3 Nb 2/3 ) 4+ for Ti 4+ and phase transition at x = 30.20. Furthermore, it was surprisingly found that the temperature coefficient of resonant frequency was near-zero (τ f = -9.2 to +9.9 ppm/°C) in a very wide range of x = 10.80-30.20.