Author:
Hatano Tsuyoshi,Fukawa Akihiro,Yamamoto Hiroki,Akiba Keiichirou,Demura Satoshi,Takase Kouichi
Abstract
Abstract
We investigated the magnetic and electric properties of nanometer-sized vanadium dioxide (VO2) particles. VO2 nanoparticles were formed by milling VO2 powder. We measured the magnetic field dependence of the magnetization of the VO2 powder and nanoparticles. The VO2 powder did not exhibit ferromagnetism, whereas the VO2 nanoparticles exhibited ferromagnetism. In addition, we fabricated samples by bridging between electrodes with the VO2 nanoparticles, and the temperature dependence of their resistance was measured. Metal-insulator transitions (MITs) were observed, and the temperature range where the MIT occurred was wider than that in a typical bulk VO2. The VO2 nanoparticles exhibited these properties of ferromagnetism and MIT possibly because of the surface and size effects of the VO2 nanoparticles. These results indicate the first observation of the competitive coexistence of ferromagnetism and MIT of VO2 nanoparticles.