Simulation of anomalous temperature-dependent ferromagnetism in p-type ZnO

Abstract Since some p-type ZnOs show the ferromagnetic magnetization increasing with the temperature in a wide temperature range, we proposed a theoretical model to simulate the observed negative temperature-dependent magnetization. This model assumes that ferromagnetism appears from the electrons located in the dopant-induced localized impurity states in the bandgap and near the valence band edge. The strong Coulomb excitation among the electrons in the impurity states leads to spin split resulting in ferromagnetism.