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Letters to Nature

Nature 413, 716-718 (18 October 2001) | doi:10.1038/35099527; Received 9 May 2000; Accepted 30 August 2000

There is a Corrigendum (25 August 2005) associated with this document.

There is a Retraction (30 March 2006) associated with this document.

Open Innovation Challenges

Magnetic carbon

Tatiana L. Makarova1,2,3, Bertil Sundqvist2, Roland Höhne4, Pablo Esquinazi4, Yakov Kopelevich5, Peter Scharff3, Valerii A. Davydov6, Ludmila S. Kashevarova6 & Aleksandra V. Rakhmanina6

  1. Ioffe Physico-Technical Institute, 194021 St Petersburg, Russia
  2. Department of Experimental Physics, Umeå University, S-90187 Umeå, Sweden
  3. Institute for Physics, Chemical Department, TU Ilmenau, D-98693 Ilmenau, Germany
  4. Department for Superconductivity and Magnetism, Leipzig University, D-04103 Leipzig, Germany
  5. Instituto de Fisica, Unicamp, 13083-970 Campinas, Sao Paulo, Brazil
  6. Institute of High Pressure Physics, 142092 Troitsk, Russia

Correspondence to: Tatiana L. Makarova1,2,3 Correspondence and requests for materials should be addressed to T.L.M. (e-mail: Email: tatiana.makarova@physics.umu.se).

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The discovery of nanostructured forms of molecular carbon has led to renewed interest in the varied properties of this element. Both graphite and C60 can be electron-doped by alkali metals1 to become superconducting; transition temperatures of up to 52 K have been attained by field-induced hole-doping of C60 (ref. 2). Recent experiments3, 4 and theoretical studies5, 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 C60. Our intention was to search for superconductivity in polymerized C60; 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.

  1. Ioffe Physico-Technical Institute, 194021 St Petersburg, Russia
  2. Department of Experimental Physics, Umeå University, S-90187 Umeå, Sweden
  3. Institute for Physics, Chemical Department, TU Ilmenau, D-98693 Ilmenau, Germany
  4. Department for Superconductivity and Magnetism, Leipzig University, D-04103 Leipzig, Germany
  5. Instituto de Fisica, Unicamp, 13083-970 Campinas, Sao Paulo, Brazil
  6. Institute of High Pressure Physics, 142092 Troitsk, Russia

Correspondence to: Tatiana L. Makarova1,2,3 Correspondence and requests for materials should be addressed to T.L.M. (e-mail: Email: tatiana.makarova@physics.umu.se).