Room Temperature Ferromagnetism of Cu-Nanoparticles under Pirolysis of Copper Porphyrin

Systematic measurements were performed using XRD, STEM, SEM and PPMS for structural and magnetic properties of different size copper nanoparticles embedded in carbon matrix synthesized by solid phase pyrolysis in different modifications of polycrystalline copper porphyrin. Our results on magnetization carried out by vibrational magnetometer in wide range of temperature for average sizes of copper nanoparticles provide strong evidence on coexistence of ferromagnetism and strong paramagnetic behavior. At low temperatures we observe a strong paramagnetic behavior, apparently due to the conduction of electrons with ballistic mean free path (large orbital magnetism). The ferromagnetic behavior with hysteresis was observed from helium up to the room temperature.