被撤回的出版物: Magnetic carbon (Retracted Article. See vol 440, pg 707, 2006)

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