Date of Graduation

Summer 2012

Degree

Master of Science in Materials Science

Department

Physics, Astronomy and Materials Science

Committee Chair

Kartik Ghosh

Keywords

ZnO, Co doped ZnO, magnetic semiconductors, hydrothermal process, nanomaterials

Subject Categories

Materials Science and Engineering

Abstract

There is great deal of interest in transparent Dilute Magnetic Semiconductors (DMS) due to their potential applications in spintronics. Nanomaterials of transition-metal doped ZnO DMS are considered as ideal systems for carrying out research in the field of spintronics as they can successfully combine magnetism and electronics in a single material. In this thesis, pure ZnO and Co-doped ZnO nanorods have been synthesized by hydrothermal method using aqueous solutions of Zn (NO3)2 .6H2O, Co (C2H3OO)2.4 H2O, and NH4OH as hydrolytic catalyst. Pure as well as transition element doped ZnO nanomaterials with different sizes and shapes have been synthesized through changing process parameters such as molarity of the precursors, pH of the final mixture, growth and annealing temperature and time during the hydrothermal process. Structural, magnetic, and optical properties are studied using available state-of-the-art techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), superconducting quantum interference device (SQUID) magnetometer and ultravioletvisible spectroscopy. XRD and SEM studies have revealed nanorods with hexagonal Wurtzite structure with length in the range of 200 to 5000 nm, and cross section in the range of 30 to 500 nm. Magnetization data suggest an existence of complex magnetic structure in the (10%, 5%, 2%) Co-doped ZnO nanomaterials. Further investigation is required to better understand the complex nature of magnetic properties in transition metal doped DMS. Understanding of DMS is critical for the future spin-electronics.

Copyright

© Sirish Chandra Bhamidipati

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