CHARACTERIZATION OF THERMISTOR-TYPE RAW MATERIALS PREPARED BY THE EVAPORATIVE DECOMPOSITION OF SOLUTIONS TECHNIQUE

摘要

The multicomponent thermistor system Co_2O_3-MnO_(2-) NiO_2 were produced using the evaporative decomposition of solutions (EDS) method.Metal acetates are used as precursors materials.One solutions is made from the precursor materials.This solution is spray dried in the EDS device at 750 ℃,causing the acetates to decompose.The typical morphology of powders created by spray drying is represented by spongy particles.In the case described,the products are dented spongy particles with very small crystalline size (30 nm) and high specific surface area.As compared with the same thermistor compositions produced by the conventional mixed oxide method the EDS powders show the familiar solid-state reactions(e.g.the formation of spinel) at the lower firing temperature.