Date of Graduation

Summer 2011

Degree

Master of Science in Materials Science

Department

Physics, Astronomy and Materials Science

Committee Chair

Kartik Ghosh

Keywords

YFeO[3], dielectrics, multiferroics, ferroelectrics, ferromagnet

Subject Categories

Materials Science and Engineering

Abstract

The development of multiferroic (MF) materials is contributing to the development of new more efficient computational technology. Previous studies have outlined the ability to tune a material's magnetic and electrical properties via the application of strain effects. Thus this thesis aims to examine whether lattice strain induces MF properties on a weak ferromagnetic material, yttrium orthoferrite (YFeO3) which has already been applied to spintronics. Bulk YFeO3 was synthesized via a solid state reaction method and the structural, magnetic, and electrical properties were characterized via a variety of techniques such as x-ray diffraction (XRD) and scanning electron microscopy (SEM). Testing confirmed the sole presence of yttrium, iron, and oxygen in all films grown via pulsed laser deposition (PLD). Superconducting Quantum Interference Device (SQUID) magnetometer measurements showed that bulk samples exhibited weak ferromagnetism (FM). Thin film analysis of the electrical properties displayed polarization-electric field (P-E) hysteresis within a typical capacitive pattern. Further analysis of the temperature dependent dielectric constant developed a clear picture of a possible ferroelectric transition around 570 K. Although further testing is required for crystalline films, this study serves to introduce the possibility of the utilization of perovskite structures which do not normally exhibit ferroelectric tendencies as such for MFs.

Copyright

© Adam Paul Hinckley

Campus Only

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