Date of Graduation

Summer 2017

Degree

Master of Science in Materials Science

Department

Physics, Astronomy, and Materials Science

Committee Chair

Kartik Ghosh

Abstract

Currently, there has been a flurry of research focused on multiferroic materials due to their potential applications. Lead (Pb)-based ferroelectric and multiferroic materials (PZT, PMN-PT, PZN-PT etc.) have been widely used for sensors, actuators, and electro-mechanical applications due to their excellent dielectric and piezoelectric properties. However, these materials are facing global restriction due to the toxicity of Pb. In this thesis, multiferroic properties of ferroelectric-ferromagnetic heterostructures consist of Pb-free perovskite oxides 0.5Ba(Zr0.2Ti0.8)O3-0.5 (Ba0.7 Ca0.3)TiO3 (BZT-BCT) and La0.7Sr0.3MnO3 (LSMO) have been studied. The heterostructures BZT-BCT/LSMO were fabricated on LaAlO3 (LAO) and Pt substrates by pulsed laser deposition. Structural and crystalline qualities of the films have been investigated through theta-2theta scan, rocking curve, and phi-scan of X-Ray diffraction (XRD) and Raman spectroscopy. Ferroelectric and ferromagnetic properties have been characterized using the Sawyer-Tower method, a SQUID magnetometer, and Ferromagnetic resonance (FMR) spectroscopy. A well-behaved magnetization-magnetic field (M-H) hysteresis has been observed in LSMO as well as heterostructures, indicating ferromagnetism in the films. FMR spectroscopy data support the static magnetization data obtained using SQUID. These results may guide the development of next-generation lead-free ferroelectric-ferromagnetic heterostructures for magnetoelectric device applications.

Keywords

epitaxy, polarization, piezoresponse, double-exchange, Gilbert damping.

Subject Categories

Other Materials Science and Engineering

Copyright

© Md Abdullah-Al Mamun

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