The aim of this paper is to study the effect of Mn concentration on the structural, magnetic and optical properties of TiO2 nanoparticles. TiO2 nano powders with Mn concentration of 0%, 0.2%, 1% and 5% were synthesized by the sol-gel method. The structural, surface morphology and average crystal grain size, optical, magnetic properties and chemical compounds of the samples are studied using XRD, FE-SEM, Uv-Vis, VSM and EDX analysis respectively. The results indicate that the samples are crystallized at anatase phase. Also, the average size of the nanoparticles is decreased by increasing Mn doping percent. The study of the optical properties shows that the absorption maximum dislocates toward higher wavelengths by adding Mn to the sample. This shift may be ascribed to the enhanced trapped electron absorption caused by the Mn-doped ions. The optical energy band gap of the doping samples shows significant reduction rather the pure state. The samples show significant paramagnetic behavior when the Mn concentration is 5%. تفاصيل المقالة