Competitive coexistence of ferromagnetism and metal--insulator transition of VO${}_2$ nanoparticles

Abstract

We investigated the magnetic and electric properties of nanometer-sized vanadium dioxide (VO${}_2$) particles. VO${}_2$ nanoparticles were formed by milling VO${}_2$ powder. We measured the magnetic field dependence of the magnetization of the VO${}_2$ powder and nanoparticles. The VO${}_2$ powder did not exhibit ferromagnetism, whereas the VO${}_2$ nanoparticles exhibited ferromagnetism. In addition, we fabricated samples by bridging between electrodes with the VO${}_2$ 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 VO${}_2$. The VO${}_2$ nanoparticles exhibited these properties of ferromagnetism and MIT possibly because of the surface and size effects of the VO${}_2$ nanoparticles. These results indicate the first observation of the competitive coexistence of ferromagnetism and MIT of VO${}_2$ nanoparticles.

6 pages, 6 figures

References in corpus (1)

• Mott transition in VO2 revealed by infrared spectroscopy and nano-imaging