NEW SUPERCONDUCTING SODIUM-NITROGEN-C60 TERNARY COMPOUND

We have prepared sodium-doped C60 utilizing the thermal decomposition of sodium azide (NaN3). The strong low-Magnetic field microwave absorp tion with a clear hysteresis was observed in the samples of NanC60 (n= 3-4), indicating the superconducting nature. By means of a SQUID measu rement, the superconducting transition temperature is found to be arou nd 12 K. Significantly, elemental analysis detected a nitrogen which w as surely produced in the process of die thermal decomposition of NaN3 . We suppose that this new superconducting phase will be NaxNyC60 wher e x is between 3 and 4, and y is unknown. This is the first supercondu cting material in Na-doped C60 without other alkali metals.