Dissertation/Thesis Abstract

Design, synthesis, crystal structure and magnetic properties of novel osmium-based B-site ordered double perovskites
by Russell, David D., M.S., California State University, Long Beach, 2016, 88; 10011271
Abstract (Summary)

Transition metal oxides (TMOs) with face centered cubic arrangement of magnetic ions are composed of triangular sub-lattices. When antiferromagnetic (AFM) interactions of the same strengths between all three pathways in triangular settings are in place, spin constraints cannot be fulfilled simultaneously and the system undergoes geometric magnetic frustration (GMF). The purpose of the work presented in this thesis is to better understand the criteria for a system to undergo GMF. To achieve this, the novel B-site ordered double perovskites Ca2ScOsO6 and Ca2.2Mg0.8 OsO6 were synthesized in polycrystalline form utilizing the conventional solid-state method. The crystal structure of these compounds were characterized through X-ray diffraction, and magnetic properties were explored through magnetic susceptibility measurements. Employing the spin-dimer analysis method, relative magnetic exchange interactions were calculated and modeled. These novel osmium-based B-site ordered double perovskites were then compared to isostructural compounds to study the effects of the osmium oxidation state on crystal structure and the exhibited properties.

Indexing (document details)
Advisor: Derakhshan, Shahab
Commitee: Bu, Xianhui, Li, Lijuan
School: California State University, Long Beach
Department: Chemistry and Biochemistry
School Location: United States -- California
Source: MAI 55/03M(E), Masters Abstracts International
Subjects: Inorganic chemistry, Condensed matter physics, Materials science
Keywords: B-site ordered double perovskite, Ca2.2Mg0.8OsO6, Ca2ScOsO6, Magnetic susceptibility, Spin dimer analysis, X-ray diffraction
Publication Number: 10011271
ISBN: 9781339471303
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