Study of structure, surface morphology and magnetic properties of 500 keV Ar2+ ion irradiated TiO2 thin films

Abstract

Ion irradiation is used as a distinct means for material property modification. It can amorphize, recrystallise and/or bring crystalline to crystalline phase transition by creating defects in the material. Here, we have study the structure and magnetic properties in TiO2 thin films annealed in oxygen and argon environment at 900 ºC after irradiating with 500 keV Ar2+ ion having ion fluence, 1 × 1015 ions/cm2. Both the films show anatase and brookite mixed phase. Films are having Ti, O and Si without change in film thickness evidenced from Rutherford's back scattering (RBS) measurement. Grain size of the film annealed in oxygen environment is 92 nm, whereas argon annealed film shows 29 nm is observed from scanning probe micrographs (SPM). Root mean square roughness (Rrms) in oxygen annealed film is 0.15 nm, which is higher than that of the argon annealed film, 0.06 nm. Further, we have established room temperature ferromagnetism (RTFM) in both the films. The RTFM may be attributed to the presence of defect in the films. © 2020 American Institute of Physics Inc.. All rights reserved.