Effects of strain, defects and crystal phase transition in mechanically milled nanocrystalline In₂O₃ powder

Abstract: In this paper, we investigated structural, optical and magnetic properties of mechanically milled In₂O₃ nanoparticles in the cubic bixbyite phase. It was observed that mechanical milling induces an important increase in the density of defects, strain and hexagonal phase transition for cubic In₂O₃ nanoparticles. Remarkably, room temperature ferromagnetism was observed after mechanical milling. The hexagonal phase of In₂O₃ nanoparticles (H-In₂O₃) which is usually obtained in a high-temperature and pressure environment was clearly observed for the sample submitted to higher milling times which considerably affects the magnetic and optical properties. The physical origin of the FM order of mechanically milled In₂O₃ nanoparticles has been ascribed to the increase in the density of defects and strain.