Dielectric ceramic of neodymium-bismuth-alkaline earth titanate type - having predetermined temp. coefft., high dielectric constant and low loss

摘要

Dielectric ceramic with predetermined temp. coefft. of the dielectric constant consists of 50-70 (wt.) % Nd titanate, 1-10% Bi titanate, 0.5-6% TiO2 and 20-35% Ba and/or Sr and/or Ca titanate. In its prepn., a mixt. of the required amts. of titanates (or corresp. oxides) and TiO2 is homogenised, with addn. of a plasticiser, moulded and fired 1-2 h in air at 1250-1350 degrees C, then cooled to room temp. This ceramic is useful in the electronics industry for (small) capacitors. It has a high dielectric constant (over 80), linear temp. characteristic and low dielectric loss (tan epsilon = 5 x 10-4 at 1 MHz).