Microwave Dielectric Properties and Far Infrared Reflectivity Spectra of the (Zr_0.8Sn_0.2)TiO₄ Ceramics with Additives

Abstract

Microwave dielectric properties and far infrared reflectivity spectra were investigated in the (Zr0.8Sn0.2)TiO4 ceramics with 1 mol% Sb2O5, Sb2O3 and Nd2O3, respectively. Dielectric constant was not significantly changed, while the unloaded Q value was affected with additives. The unloaded Q of the pure (Zr0.8Sn0.2)TiO4 specimens was higher than that of the specimens with Sb2O3 and/or Nd2O3, but lower than that of the specimens with Sb2O5. The high unloaded Q value of 6600 at 7 GHz was obtained for the specimens with 1 mol% Sb2O5 due to elimination of oxygen vacancies. The effects of additives on the intrinsic microwave losses of the specimens were investigated by the infrared reflectivity spectra from 50 to 4000 cm-1, which were evaluated using the Kramers-Kronig analysis and classical oscillator model. The relative tendency of microwave dielectric properties calculated from the reflectivity data was in good agreement with the results by the Hakki and Coleman's method.

Effect of Post-Annealing on the Microstructure and Microwave Dielectric Properties of Ba(Co0.7Zn0.3)1/3Nb2/3O3 Ceramics

“…The results in Table 2 show that high densities were obtained for all ceramics materials regardless of the processing conditions. This confirms that, from certain density values on (>90%), the Q f value is independent of the density in agreement with previous data [13]. Indeed, during the sintering step, the improved Q f value could be linked to differences in the ceramic microstructure as shown in Table 2, with a high Q f value of 96132 was obtained for the BCZN specimen (S2), with a grain size of 0.6-2.3 microns.…”

Microwave dielectric properties of Al2O3 ceramics co-doped with MgO and Nb2O5

“…1. But for the higher Q 9 f value, the higher densities might not be the main reason because previous investigations on Al 2 O 3 and other systems show that the influence of the density on the Q 9 f value is limited if the relative densities higher than 95 % [4,7,[23][24][25]. One possible main reason for the higher Q 9 f value of the MgO/Nb 2 O 5 co-doped samples is the charge compensation.…”

Effects of V2O5 addition on the phase-structure and dielectric properties of zinc titanate ceramics

“…Q value was found to decrease for V 2 O 5 -doped zinc metatitanate-based ceramics in microwave region as compared with single-phase hexagonal ZnTiO 3 ceramics. Microwave dielectric loss is mainly caused by second phases, oxygen vacancies, grain sizes and densification or porosity [20,21]. From Fig.…”