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MULTIFERROIC BISMUTH FERRITE-LEAD TITANATE AND IRON-GALLIUM CRYSTALLINE SOLUTIONS: STRUCTURE-PROPERTY INVESTIGATIONS

by Wang, Naigang

Abstract (Summary)
Recently, multiferroics-defined as materials with coexistence of at least two of the ferroelectric, ferroelastic and ferromagnetic effects-have attracted enormous research activities. In this thesis, the structure and properties of multiferrioic BiFeO3-x%PbTiO3 and Fe-x%Ga crystalline solutions were investigated. First, the results show that modified BiFeO3-PbTiO3 based ceramics have significantly enhanced multiferroic properties, relative to BiFeO3 single crystals. The data reveal: (i) a dramatic increase in the induced polarization; and (ii) the establishment of a remnant magnetization by a breaking of the translational invariance of a long-period cycloidal spin structure, via substituent effects. In addition, temperature dependent magnetic permeability investigations of BiFeO3-xPbTiO3 crystalline solutions have shown that aliovalent La substitution results in a significant increase in the permeability. Second, room temperature high-resolution neutron and x-ray diffraction studies have been performed on Fe-x%Ga crystals for 12Bibliographical Information:

Advisor:W. T. Reynolds; Jiefang Li; Dwight Viehland

School:Virginia Polytechnic Institute and State University

School Location:USA - Virginia

Source Type:Master's Thesis

Keywords:materials science and engineering

ISBN:

Date of Publication:07/20/2005

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