Influence of nickel doping on the structural, optical and magnetic properties of TiO2 diluted magnetic semiconductor nanoparticles prepared by high energy ball-milling technique

In the present work, Ni-doped TiO2 samples have been successfully prepared by high energy ball milling at different milling time. The structural, optical and magnetic properties of the samples prepared at varying time intervals were studied using X-ray diffractometer (XRD), Scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), UV–Visible spectrophotometer (UV–VIS), Vibrating sample magnetometer (VSM) and Electron paramagnetic resonance (EPR). XRD study revealed the presence of anatase structure for the Ni doped TiO2 samples milled at 8 and 16 h while a secondary phase of TiO2 with (211) plane of brookite appears in 24 h milled sample. From the optical absorption study of the samples, the observed red shift of absorption band edge with increasing milling time indicates the substitution of Ni into TiO2 lattice. VSM study of the sample milled at 24 h showed the presence of ferromagnetism. EPR measurements confirm the presence of ferromagnetism from the g-value of Ni doped TiO2 nanoparticles.