Magnetic and Optical Studies in K3C60

Maw-Kuen Wu ； Patrick P. T. Leong ； Chien-Ming Lei ； Jjun-Hwei Hwang ； Chung-Yuan Mon

《Chinese Journal of Physics》 35卷6S期 (1997/12) Pp. 935-942

並列摘要

We report the observation of new phase of bulk superconducting K3C60 with anomalous magnetic properties which suggest the presence of p-wave superconductivity. The samples are prepared by mixing stoichiometric amounts of K and C60 and annealed in vacuum for a period of 5 days at 500”C. The magnetic susceptibility showed a temperature-hysteresis pattern which was positive at 0.2 G and negative at 2 G or above. Two distinct Tc onsets were seen at 0.2 G while three distinct Tc onsets were seen at higher magnetic fields. Photoluminescence and X-ray measurements suggested the possibility of polymerization of the C60 molecules. A comparison with K3C60 samples annealed at 400°C for 5 days indicated that the annealing temperature was critical to the final product outcome.