Giant Paramagnetism and Ferromagnetism of Copper Nanoparticles in a Carbon Matrix

POSTER

Abstract

Solid-phase pyrolysis of polycrystalline copper phthalocyanine (CuPc, Pc=C32N8H16) yielded Cu nanoparticles encapsulated in a graphite-like carbon shell - Cu@C nanocomposites. Magnetic measurements in series of average sizes of copper nanoparticles in the range of 5-40 nm were conducted by a vibrational magnetometer in the temperature range 10-300 K and magnetic field up to the 60 kOe. Giant paramagnetism, apparently due to conduction electrons with ballistic mean free path (large orbital magnetism) was detected for nanoparticles with small average size of Cu nanoparticles, 5-7 nm. At temperature T= 10K the value of the specific susceptibility is of order 1.5×10-4 emu/gOe. Ferromagnetism (Ms ≈ 0.5 emu/gCu) was also detected in Cu@C nanocomposites from helium up to room temperature.

*The work was supported by the RA MES State Committee of Science, in the frames of the research project No. 15T-1C249. The work at California State University was supported by the National Science Foundation-Partnerships for Research and Education in Materials under Grant DMR-1523588.

Presenters

  • Armen Kocharian

    • Physics Department, Cal State Univ- Los Angeles
    • Physics, Cal State Univ- Los Angeles

Authors

  • Medhanie Estiphanos

    • Physics Department, Cal State Univ- Los Angeles
    • Physics, Cal State Univ- Los Angeles

  • Eduard Sharoyan

    • Institute for Physical Research, NAS RA
    • Institute for Physical Research

  • Aram Manukyan

    • Institute for Physical Research, NAS RA
    • Institute for Physical Research

  • Harutyun Gyulasaryan

    • Institute for Physical Research

  • Oscar Bernal

    • Physics Department, Cal State Univ- Los Angeles
    • Department of Physics and Astronomy, California State University
    • Physics and Astronomy, California State University
    • Physics, Cal State Univ- Los Angeles

  • Armen Kocharian

    • Physics Department, Cal State Univ- Los Angeles
    • Physics, Cal State Univ- Los Angeles