Magnetic properties of monodisperse NiHx nanopairticles and comparison to those of monodisperse Ni nanoparticles

Abstract

We produced, for the first time, monodisperse NiHx nanoparticles with particle diameters of 7.0 nm and investigated their magnetic properties. We also produced monodisperse Ni nanoparticles with nearly the same particle diameters as those of NiHx nanoparticles as a comparison. The magnetic properties of NiHx nanoparticles were quite different from those of Ni nanoparticles. We observed two compositional phases in NiHx nanoparticles, similar to bulk material: one is the nearly pure Ni phase with the blocking temperature (TB) of 11 K and the other is the hydride phase. We observed T-B of 40 K in Ni nanoparticles.