By means of the silicon carbonization technique using the graphite powder containing Dy_2O_3 or Gd_2O_3, porous SiC in which Dy or Gd were finely dispersed, was successfully synthesized. The magnetic impurity densities estimated from the analysis of the magnetic properties of the Dy/Gd doped samples. There is little difference between the effective carrier densities and the magnetic impurity densities for the Gd doped samples. In contrast, for the Dy doped samples, the effective carrier densities were much larger than the magnetic impurity densities. These results indicated that Dy might be mainly doped near the surface of the SiC wafer. Hence the effective carrier densities of the Dy doped samples in the near surface region were considered to significantly increase in contrast to the ND samples. As a result, the power factors of the Dy doped samples were much improved to exhibit the highest value of 5.8 × 10~(-5) W/mK~2 at 897 K.
展开▼
