Chemical preparation of high-field zinc oxide varistors

Chemical preparation methods were developed for high-field ZnO varistors in which precipitation techniques were used to prepare precursor powders. Varistors were made by sintering uniaxially pressed pellets in the range of 675 to 740 C in air. Varistor properties included electric fields(E) in the 10 to 100 kV/cm range at current densities(J) of 5A/cm(2), nonlinearity coefficients((ALPHA)) greater than 30 at 2.5 less than or equal to J less than or equal to 5.0 A/cm(2), and densities in the range of 65 to 99% of theoretical depending both on sintering temperature and composition.