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dc.contributor.authorMonfared, Sara
dc.date.accessioned2022-06-02T13:55:15Z
dc.date.available2022-06-02T13:55:15Z
dc.identifier.urihttp://hdl.handle.net/10464/16384
dc.description.abstractThis thesis consists of three parts. The first section is about CoFe2O4-BiFeO3 core-shell multiferroic nanocomposite synthesized via a two-step wet-chemical process. The presence of both spinel and perovskite constituents as well as the core-shell structure of nanocomposite have been identified using x-ray diffraction and high-resolution transmission electron microscopy, respectively. Low temperature (5 K) magnetic measurement exhibited a significant exchange bias in the core-shell nanocomposite which confirms promising connectivity of the constituents in the interface. An enhancement in magneto-dielectric of the core-shell nanocomposite over the CoFe2O4-BiFeO3 (0-3)-type nanocomposites has been seen. Further study on the magneto-loss demonstrated the contribution of the magneto-electric and Maxwell-Wagner effects in magneto-dielectric of the core-shell nanocomposite. The second part of this thesis has focused on the bulk of SrFe(12−2x)CoxRuxO19 (x = 0, 0.1, 0.2, 0.3, 0.4) which have been synthesized through the solid-state reaction process. DC magnetic measurement at room temperature exhibited a significant reduction in the coercive field of samples as the concentration of dopants increased. Contrary, an increase in the saturation magnetization was observed in the doped samples. Furthermore, a transition from conical to uniaxial anisotropy has been seen for the doped samples above x=0.3. Thin films of SrFe(12−2x)CoxRuxO19 / (111) SrTiO3 fabricated by a pulsed laser deposition technique, have been studied in the last part of this work. High-resolution parallel beam x-ray diffraction results have shown single orientations for all thin films except one. The thickness of thin films has been determined by the x-ray reflectivity measurement. A certain level of mosaicity has been detected in the prepared films using the rocking curve measurement. The strain and the epitaxial growth of thin films have been investigated utilizing the reciprocal space map technique. Finally, in-plane pole figure measurements revealed high textured films with three-fold and six-fold hexagonal symmetry. The formation of a perpendicular anisotropy in Co-Ru doped Sr-M thin films has been detected from room temperature magnetic measurement. The distribution of Co2+ and Ru4+ ions in different interstitial spaces, the thickness of films, and change in the magneto-anisotropy with a concentration of dopants have a significant effect on the magnetic characteristic of thin films.en_US
dc.language.isoengen_US
dc.publisherBrock Universityen_US
dc.subjectNanocompositeen_US
dc.titleFabrication and Characterization of CoFe2O4-BiFeO3 Core Shell Nanocomposite and SrFe(12−2x)CoxRuxO19 Hexaferritesen_US
dc.typeElectronic Thesis or Dissertationen_US
dc.degree.namePh.D. Physicsen_US
dc.degree.levelDoctoralen_US
dc.contributor.departmentDepartment of Physicsen_US
dc.degree.disciplineFaculty of Mathematics and Scienceen_US


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