Temperature-stable dielectric ceramics in Ba₄Nd₂Ti₄Ta₆O₃₀/(La_0.1Bi_0.9)₂Ti₂O₇ biphase system

Abstract

Biphase dielectric ceramics in the system of (1 − x)Ba4Nd2Ti4Ta6O30/ x(La0.1Bi0.9) 2Ti2O7 were investigated to obtain a near-zero temperature coefficient of dielectric constant. With the increase in x, the dielectric constant increased slightly, and the temperature coefficient changed from negative to positive. High dielectric constant of ε = 143 and good temperature stabibility (τ ε = −48 ppm/ °C) were achieved in a composition of x = 0.45, and the increased dielectric loss became the new problem.

Dielectric Properties and Sintering Characteristics of CaTiO3-(Li1/2Nd1/2)TiO3 Ceramics

“…Hitherto, several materials with high dielectric constant have been reported and most of them are focused on plural elements system including TiO 2 , such as BaO-Nd 2 O 3 -TiO 2 -Ta 2 O 5 [1,2], BaO-Sm 2 O 3 -TiO 2 [3,4], CaO-Li 2 O-Ln 2 O 3 -TiO 2 [5][6][7][8][9], or (A +1 1/2 A +3 1/2 )TiO 3 system [10]. Among of these materials, compositions with perovskite structure based on (A +1 1/2 A +3 1/2 )TiO 3 system or CaTiO 3 system have superior microwave properties: ε = 81, Q f = 6150 GHz, τ f = +17 ppm/ • C for 0.6(Li 1/2 Sm 1/2 )TiO 3 -0.4(Na 1/2 Sm 1/2 )TiO 3 ceramics [10], ε = 110, Q f = 4500 GHz, τ f = +7 ppm/ • C for CaOSrO-Li 2 O-Ln 2 O 3 -TiO 2 (Ln = Sm, Nd) system [5], ε108,Q f = 17200 GHz in (Ca 1−x Nd 2x/3 )TiO 3 system [11] and 0.67Ca 2/5 Sm 2/5 TiO 3 -0.33Li 1/2 Sm 1/2 TiO 3 ceramics with ε = 95.5, Q f = 7200 GHz, τ f = 0 ppm/ • C [9].…”