Critical behaviors of the conductivity and dielectric constant of Ti 3SiC2/Al2O3 hybrids

Abstract

Ti3 Si C2 Al2 O3 hybrids were prepared by a spark plasma sintering process. The effective dc conductivity of the hybrids was measured at room temperature, which agrees with the percolation theory and follows the power law around the percolation threshold. The ac conductivity and dielectric constants of the hybrids were also characterized and follow the power law when the concentration of the conductive phase is close to the percolation threshold; meanwhile, the dielectric constant could increase over three orders of magnitude compared with Al2 O3. © 2007 American Institute of Physics.