MICROWAVE DIELECTRIC CERAMICS COMPOSED OF BARIUM, NEODYMIUM, GADOLINIUM, TITANIUM AND BISMUTH OXIDES

摘要

Microwave dielectric ceramics composed of barium, neodymium, gadolinium, titanium and bismuth oxides, characterized in that the contents in mole fractions are as follows: x(BaO) = 16 - 20 mol %, x(Nd2O3) = 10 - 17 mol %, x(Gd2O3) = 0 - 8 mol %, x(TiO2) = 66 - 72 mol % and x(Bi2O3) = 0 - 3 mol %, are calcined for 1 to 10 hours at 1000 °C to 1150 °C and sintered for 15 minutes at 1320 °C. The dielectric constant (k') depends on the ratio of the elementary oxides and is from 90 to 99, whereby the quality factor (Q x f) remains higher than 5000. The temperature coefficient of resonant frequency τf is precisely controllable by the quantity of added Gd2O3.