Effect of Non-Stoichiometry Oxygen Content on the Magnetization of La1.5Sr0.5NiO4+δ

Abstract

We report on magnetization measurements of La1.5Sr0.5NiO4+δ for δ=0.01 and δ=−0.01. Zero field-cooled and field-cooled bulk magnetization measurements were performed parallel to the Ni–O planes of single crystals, and on a polycrystalline δ=0.01 sample. Striking differences in the magnetization curves are observed between the two doping levels that are identifiable in polycrystalline δ=0.01. The bulk magnetization differences indicate a crossover in the magnetic properties of La2−x Sr x NiO4+δ at half doping level, which can be used as a simple non-destructive way to determine whether La1.5Sr0.5NiO4+δ is under or over half doping.