SYNTHESIS AND STRUCTURE-PROPERTY RELATIONSHIPS OF THE AAg2M[VO4]2 TYPE OF COMPOUNDS

dc.contributor.advisorMöller, Angela
dc.contributor.committeeMemberGuloy, Arnold M.
dc.contributor.committeeMemberJacobson, Allan J.
dc.contributor.committeeMemberXu, Shoujun
dc.contributor.committeeMemberLitvinchuk, Alexander P.
dc.creatorAmuneke, Ngozi Ebere 1986-
dc.date.accessioned2015-08-25T00:51:35Z
dc.date.available2015-08-25T00:51:35Z
dc.date.createdAugust 2013
dc.date.issued2013-08
dc.date.updated2015-08-25T00:51:35Z
dc.description.abstractThis dissertation focuses on the synthesis and structural characterization of a series of new compounds belonging to the family: AAg2M[VO4]2. We have modified the A-site spacer with the divalent metals: Sr2+ and Ba2+ and monovalent metals: K+, Rb+, and Ag+ which are representatives of chemical pressure by size and charge differences. The magnetic M-site cation can also be altered with respect to size and charge differences. Here, we have investigated the spin systems Cu2+ (S = ½), Ni2+ (S = 1), Co2+ (S = 3/2), Mn2+ (S = 5/2), Fe3+ (S = 5/2), and Cr3+ (S = 3/2). These are arranged on a triangular lattice connected exclusively via vanadates as a linker. Super-super exchange pathways via the vanadates are important for the magnetic correlations, therefore the relative orientation of these non-magnetic linkers with respect the M-site cation is of utmost importance. Here we have investigated this aspect of structure-property relationships by several experimental techniques: X-ray diffraction to examine the crystal structure, spectroscopic methods aiming at the vibrational and electronic structures, thermodynamic, and neutron diffraction measurements. A detailed structural description is presented discussing the alteration on the A and M-sites and the finding of “tunable” magnetic properties related to the orientation of the vanadate. In conclusion, those with transition metal cations with dn > 5 are ferromagnets whereas those with dn ≤ 5 belong to the rare class of geometrically frustrated antiferromagnets.
dc.description.departmentChemistry, Department of
dc.format.digitalOriginborn digital
dc.format.mimetypeapplication/pdf
dc.identifier.urihttp://hdl.handle.net/10657/1062
dc.language.isoeng
dc.rightsThe author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s).
dc.subjectSynthesis
dc.subjectCharacterization
dc.subjectChemical pressure
dc.subjectSpin systems
dc.subjectTriangular lattice
dc.subjectVanadates
dc.subjectSuper-super exchange
dc.subjectMagnetic properties
dc.subjectStructure-property relationships
dc.subjectFerromagnets
dc.subjectGeometrically frustrated
dc.subjectAntiferromagnets
dc.subjectX-ray diffraction
dc.subjectCrystals
dc.subject.lcshChemistry
dc.titleSYNTHESIS AND STRUCTURE-PROPERTY RELATIONSHIPS OF THE AAg2M[VO4]2 TYPE OF COMPOUNDS
dc.type.dcmiText
dc.type.genreThesis
thesis.degree.collegeCollege of Natural Sciences and Mathematics
thesis.degree.departmentChemistry, Department of
thesis.degree.disciplineChemistry
thesis.degree.grantorUniversity of Houston
thesis.degree.levelDoctoral
thesis.degree.nameDoctor of Philosophy

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