Abstract
Silicon borides were prepared by arc melting in argon atmosphere using silicon and boron powders in a boron content range from 80 to 94mol%. As-melted specimens consisted of SiBn, and free Si. The contents of free Si decreased from 30 to 3vol% as the boron content in raw material increased from 80 to 94mol%. The as-melted specimens were heat-treated in argon atmosphere at temperatures of 1400 to 1700K. During heat treatment, free Si reacted with SiBn near the SiBn-Si boundary to form SiB4, and as the result SiBn, -SiB4 composites were obtained. The SiBn-SiB4 composites showed larger electrical conductivity and smaller thermal conductivity than the as-melted specimens, which contributes to improvement of thermoelectrical property.
