Electrical conductivity of ceramics of SiC-AlN, SiC-BeO, Al/sub 2/O/sub 3/ in the temperature range 300-1800 K

The electrophysical properties of SiC-AlN, SiC-BeO, and Al/sub 2/O/sub 3/ ceramics at high temperatures were investigated. Samples of ceramics were obtained by the hot-pressure method. The investigation shows that specific resistance at 300 K is: 10/sup 12/ /spl Omega/.cm, 10/sup 9/ /spl Omega/.cm, and 10/sup 7/ /spl Omega/.cm for SiC-BeO ceramics containing 0.5%, 1.0%, and 2.0% BeO respectively; 10/sup 12/ /spl Omega/.cm, 10/sup 8/ /spl Omega/.cm, and 10/sup 6/ /spl Omega/.cm for SiC-AlN ceramics containing /spl ges/50%, 20% and 10% AlN respectively; and 10/sup 1/2 /spl Omega/.cm for Al/sub 2/O/sub 3/. The specific resistance of all of these ceramics at 1500 K is about 10 /spl Omega/.cm.