High coercivity and exchange coupling of NiNiO nanocomposite film

Abstract

A coercivity of 2.4 kOe was achieved at room temperature after magnetic annealing a pure Ni film at 650 K for 20 min under O2 partial pressure of 0.001 torr. The interface structure of NiNiO during the formation of NiO under magnetic field and the small grains may be responsible for the large coercivity. Additionally, the surface NiO, dipolar interaction of Ni particles, and the composition of NiO inside the film may affect the coercivity as well. © 2005 American Institute of Physics.