Room temperature ferromagnetism in Mn doped TiO-2 thin films:Electronic structure and Raman investigations

摘要

In this work dc-magnetization, electronic structural, and Raman investigations of Ti(1-x)Mn-xO-2 (x = 0.00, 0.05, 0.10, and 0.15) thin films deposited on fused-quartz substrate by a simple and cost effective spray pyrolysis technique have been reported. X-ray diffraction revealed the formation of pure anatase TiO-2 phase devoid of elemental Mn clusters in all the Mn incorporated TiO-2 films. It is established by x-ray photoelectron spectroscopic (XPS) measurements that Ti ions substituted by Mn ions in both divalent and trivalent states in the TiO-2 matrix. No peak corresponding to Mn~+4 could be evidenced by XPS. The Raman study has further established the formation of TiO-2 in anatase structure in both pure TiO-2 and Mn-doped TiO-2 films. The Ti(1-x)Mn-xO-2 films with x≥ 0.05 exhibit ferromagnetic ordering at room temperature which arises most likely due to formation of bound magnetic polarons.