Ferromagnetism in water-doped vanadium oxide nanotubes

Abstract

We have investigated the magnetic properties of vanadium oxide nanotubes (VO(x)-NTs) of various V(4+) concentrations. Ferromagnetic response was observed at similar to 100 K only in the V(4+)-rich water-intercalated VO(x)-NTs, whose saturation moment is close to that of Li-doped VO(x)-NTs, a recently-reported room-temperature ferromagnet. The ferromagnetism may have to do with charge localization as well as the spin concentration giving rise to removal of spin frustration according to our previous study. (C) 2010 American Institute of Physics. [doi:10.1063/1.3463425]