Giant Paramagnetism of Copper Nanoparticles in Nanocomposites Cu@C

The copper nanoparticles in nanocomposites Cu@C, encapsulated in graphitized carbon shell was obtained by the solid-phase pyrolysis method of polycrystalline phthalocyanine (CuPc, Pc$=$C$_{\mathrm{32}}$N$_{\mathrm{8}}$H$_{\mathrm{16}})$. The average sizes of the nanoparticles are in the range of 2-6 nm. Magnetic measurements were carried out by vibrational magnetometer in the temperature range 10-300~K. At low temperatures (\textless 70K) we observed a giant paramagnetism,~apparently due~to the (ballistic) conduction electron (large orbital magnetism). The values of the specific susceptibility at~$T$~$=$ 10K with magnetic specific~susceptibility of 5\textbullet 10$^{\mathrm{-5}}$~emu/g\textbullet Oe order. This work was supported by the RA MES State Committee of Science, in the frames of the research project SCS-13-1C090. The work at California State University was supported by the National Science Foundation-Partnerships for Research and Education in Materials under Grant DMR-1523588.