Structural, optical, and magnetic properties of Cu‐doped TiO2 samples

Abstract

We report here the microstructure, optical, and magnetic properties of Cu‐doped TiO2 (Ti1−xCuxO2) nanopowder samples with x = 0.02, 0.04, and 0.06 prepared by a solid‐state reaction method. XRD studies indicated the incorporation of Cu into the TiO2 lattice. Ultraviolet‐visible spectroscopy (UV–vis) measurements revealed that the band gap decreased due to the incorporation of Cu. Photoluminescence (PL) results showed an enhanced photoluminescence property associated with oxygen vacancies from TiO2 due to the incorporation of Cu. Magnetic investigations demonstrated that all of the samples had room temperature ferromagnetism (RTFM). RTFM was observed in the Ti0.98Cu0.02O2 samples annealed at 500°C and reduced RTFM was clearly observed in the samples annealed at high temperatures of 600 and 700°C. Furthermore, the saturation magnetic moment decreased with increasing Cu content for the samples annealed at 500ᴼC with different doping Cu contents, due to the increased Cu atoms occupying neighbouring cation lattice sites, which resulted in an antiferromagnetic configuration. The results demonstrated that defects and/or oxygen vacancies, and the distances between nearest‐neighbour Cu atoms, have a significant influence on ferromagnetism in Cu‐doped TiO2 powder samples.