Magnetic and optical properties of Mn-doped SnO2 films

Abstract

ABSTRACTMagnetic nanoparticles have drawn much attention due to their potential in magnetic recording as well as many biological and medical applications such as magnetic separation, hyperthermia treatment, magnetic resonance contrast enhancement and drug delivery. The magnetic fields generated by these nanoparticles can be used for diagnostics in Magnetic Resonance Imaging (MRI) etc. Manganese doped tin dioxide (SnO2:Mn) possess interesting physical and chemical properties. The physical and chemical properties of the particles themselves like the size, shape, crystallinity and composition, will control the magnetic properties and response of the particles to magnetic fields. Our work is rooted to control the properties of the particles as well as tailor their magnetic properties for specific applications. In this study, SnO2: Mn films with different Mn doping concentrations (0-3 mol%) were deposited on the glass substrates by sol-gel dip coating technique. XRD patterns shows tetragonal structure for all the SnO2:Mn films and crystallite size decreased as Mn doping concentration increased from 0 - 3 mol%. The magnetic property shows that pure SnO2 film is diamagnetic and 1- 3 mol% SnO2:Mn films posses room temperature ferromagnetism. The optical properties of the films revealed that transmittance of the films decreased with increase in Mn doping concentration. The optical energy band gap values (3.55 eV-3.71 eV) increased with the increase in Mn doping concentrations. Such SnO2:Mn films with structural, optical and magnetic properties can be used as dilute magnetic semiconductors.