Different nonlinear conduction mechanism between α-SiC and β-SiC

The nonlinear electrical conductivity of β-SiC and α-SiC was investigated. β-SiC has an excellent nonlinear electrical conductivity when the particle size varies from 14~21 μm. Compared with α-SiC, the parallel particle size β-SiC micro-powder has lower resistance and greater nonlinear electrical conduction coefficient which is marked by β. The difference of electrical conductivity between β-SiC and α-SiC is interpreted from the crystal structure and shape. It is shown that the cubic crystal structure β-SiC has smaller contact area than hexagonal α-SiC with induced higher contact potential barrier. Under high voltage, the electrical conduction mechanism of the tetrahedral parallel configuration β-SiC crystal is more complex than the anti-parallel configuration α-SiC crystal