Optical and Magnetic Behaviour of Metal Doped-CdS Nanostructures

Abstract

Spintronics represents the field of electronics, in which the spin of electron is utilized along with its charge. Dilute magnetic semiconductors (DMS) materials are promising for future spintronic device applications. A lot of research has been devoted to generate magnetism in semiconductor materials via doping of transition metals, known as DMS materials. However, the origin of magnetism remains controversial till date. There are various mechanisms (or theories) which have been proposed in order to explain the origin of magnetism in these DMS materials such as Ruderman-Kittel-Kasuya-Yosida (RKKY), double exchange interactions, superexchange interactions, and bound magnetic polaron (BMP). Also, from the application point of view, low TC further hinders their practical utility, and thus, many efforts have been made to find ferromagnetic DMS having TC higher than room temperature. This has motivated us to carry out investigations in order to achieve and understand the origin of observed magnetism in DMS materials. In present thesis work, the structural, optical and magnetic properties of transition and rare earth metal-doped CdS nanostructures, nanoparticles and nanorods, synthesized using chemical synthesis route, have been examined. The properties have been studied using various techniques viz. transmission electron microscope (TEM), High resolution (HRTEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), UV-Visible spectroscopy (UV-Vis.), photoluminescence spectroscopy (PL) and vibrating sample magnetometer (VSM).