Effect of vacancy defects on electronic structure and ferromagnetism in pristine In2O3 nanostructures: An experimental study and first-principles modeling

Abstract

Single-phase In2O3 cubic crystal structure nanorods and nanoparticles with defined morphology and microstructure were prepared by the hydrothermal method followed by an annealing process. High-resolution transmission electron microscopy analysis indicated the formation of In2O3 rectangular nanorods and spherical nanoparticles. Magnetic measurements revealed room temperature ferromagnetism in the prepared samples, which could be correlated to the increased number of intrinsic defects, especially dangling bonds on corners and edges of nanorods and nanoparticles. First-principles modeling established these In2O3 nanoparticles as a system of ferromagnetic clusters of large spins connected by a network of weak ferromagnetic interactions via indium vacancies on the (111) surface. A theoretical model was proposed to explain the coexistence of room temperature ferromagnetism and semiconductive electronic structure in In2O3 nanostructures. The present study provides new evidence and insight into vacancy defect-mediated ferromagnetism.