Magnetic carbon

The discovery of nanostructured forms of molecular carbon has led to renewe d interest in the varied properties of this element. Both graphite and C-60 can be electron-doped by alkali metals(1) to become superconducting; trans ition temperatures of up to 52 K have been attained by field-induced hole-d oping of C-60 (ref. 2). Recent experiments(3,4) and theoretical studies(5,6 ) have suggested that electronic instabilities in pure graphite may give ri se to superconducting and ferromagnetic properties, even at room temperatur e. Here we report the serendipitous discovery of strong magnetic signals in rhombohedral C-60. Our intention was to search for superconductivity in po lymerized C-60; however, it appears that our high-pressure, high-temperatur e polymerization process results in a magnetically ordered state. The mater ial exhibits features typical of ferromagnets: saturation magnetization, la rge hysteresis and attachment to a magnet at room temperature. The temperat ure dependences of the saturation and remanent magnetization indicate a Cur ie temperature near 500 K.