OICC Press International Nano Letters 2228-5326 8 1 (March 2018) 2018 02 10 Structural, optical, and magnetic study of Ni-doped TiO2 nanoparticles synthesized by sol–gel method 10.1007/s40089-018-0225-7 EN M. Manzoor Material and Nano Science Research Lab (MNRL), Department of Physics, Government College University Lahore, Punjab, 54000, PK A. Rafiq Material and Nano Science Research Lab (MNRL), Department of Physics, Government College University Lahore, Punjab, 54000, PK M. Ikram Solar Cell Applications Research Lab, Department of Physics, Government College University Lahore, Punjab, 54000, PK M. Nafees Material and Nano Science Research Lab (MNRL), Department of Physics, Government College University Lahore, Punjab, 54000, PK S. Ali Material and Nano Science Research Lab (MNRL), Department of Physics, Government College University Lahore, Punjab, 54000, PK Solar Cell Applications Research Lab, Department of Physics, Government College University Lahore, Punjab, 54000, PK Journal Article 2018 02 10 Abstract In this research, the effects of transition metal (Ni) doping to metal-oxide nanoparticles (TiO 2 ) were studied. Various weight ratios (5, 10, 15, and 20%) of Ni-to-TiO 2 nanoparticles were synthesized using the sol–gel technique. These doped nanoparticles were prepared using titanium butoxide and nickel nitrate as precursors and methanol as a solvent. The effects of Ni doping to TiO 2 were examined using a variety of characterization techniques, X-ray diffraction (XRD), Fourier-transform-infrared (FTIR) spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy, field-emission scanning electron microscopy (FESEM), and vibrating sample magnetometer (VSM). The XRD reveals that the Ni-doped TiO 2 crystallizes in a tetragonal structure with anatase phase. The particle size and lattice strain were calculated by Williamson–Hall equation. The presence of strong chemical bonding and functional groups at the interface of TiO 2 nanoparticles was confirmed by FTIR. The optical properties of undoped and doped samples were recorded by UV–Vis spectroscopy. The saturation magnetization ( M s ) was found higher for undoped as compared to doped samples. The surface morphology and the element structure of the Ni-doped TiO 2 nanoparticles were examined by FESEM.