Graduation Year
2010
Document Type
Dissertation
Degree
Ph.D.
Degree Granting Department
Physics
Major Professor
Sarath Witanachchi, Ph. D.
Co-Major Professor
Pritish Mukherjee, Ph. D.
Committee Member
Hariharan Srikanth, Ph. D.
Committee Member
George S. Nolas, Ph. D.
Committee Member
Lilia M. Woods, Ph. D.
Keywords
Pulsed Laser Deposition, Magnetic Anisotropy, Spintronics, Dilute Magnetic Semiconductor, Cobalt Ferrite, CoFe2O4, Lead Zirconium Titanate, PZT, Manganese or Vanadium Doped Zinc Oxide, ZnO:Mn, ZnO:V, LSMO, RKKY
Abstract
Multiferroic materials exhibit unique properties such as simultaneous existence of
two or more of coupled ferroic order parameters (ferromagnetism, ferroelectricity,
ferroelasticity or their anti-ferroic counterparts) in a single material. Recent years have
seen a huge research interest in multiferroic materials for their potential application as
high density non-volatile memory devices. However, the scarcity of these materials in
single phase and the weak coupling of their ferroic components have directed the
research towards multiferroic heterostructures. These systems operate by coupling the
magnetic and electric properties of two materials, generally a ferromagnetic material and
a ferroelectric material via strain. In this work, horizontal heterostructures of composite
multiferroic materials were grown and characterized using pulsed laser ablation technique.
Alternate magnetic and ferroelectric layers of cobalt ferrite and lead zirconium titanate,
respectively, were fabricated and the coupling effect was studied by X-ray stress analysis.
It was observed that the interfacial stress played an important role in the coupling effect
between the phases. Doped zinc oxide (ZnO) heterostructures were also studied where
the ferromagnetic phase was a layer of manganese doped ZnO and the ferroelectric phase
was a layer of vanadium doped ZnO. For the first time, a clear evidence of possible room
temperature magneto-elastic coupling was observed in these heterostructures. This work
provides new insight into the stress mediated coupling mechanisms in composite
multiferroics.
Scholar Commons Citation
Mukherjee, Devajyoti, "Growth and Characterization of Epitaxial Thin Films and Multiferroic Heterostructures of Ferromagnetic and Ferroelectric Materials" (2010). USF Tampa Graduate Theses and Dissertations.
https://digitalcommons.usf.edu/etd/3622