No abstract

Silicon wafers with different carbon contents have been characterized by Fourier transform infrared spectroscopy technique. An infrared absorption band at 1207cm-1 can be newly observed in the case of carbon content being above 1.7×1017/cm3, whose intensity increases with an increase of carbon concentration in silicon crystal. More interestingly, the 1207cm-1 band cannot be influenced by the long-time annealing in the temperature range of 450-1250oC, suggesting the high thermal stability of this carbon-related defect, which might be related to the presence of silicon carbide in silicon crystals.

No abstract

No abstract

A n effective attractive Hubbard model is applied to explain the observed non-Korringa relation in doped fullerenes, which leads to a reduced Pauli susceptibility. The results basically agree with the experiments for K3C60, Rb3C60 and RbCszQo. It implies that the pair correlation on site possibly plays an important role in the normal state for doped fullerenes.