Size and Shape Controlled Synthesis and Superparamagnetic Properties of Spinel Ferrites Nanocrystals

Spinel ferrite;Superparamagnetism;Synthesis;Nanocrystals;Size and shape control;Superlattices;Superstructures

Song, Qing ; Chemistry and Biochemistry

University:Georgia Institute of Technology

Department:Chemistry and Biochemistry

关键词: Spinel ferrite;    Superparamagnetism;    Synthesis;    Nanocrystals;    Size and shape control;    Superlattices;    Superstructures;   

Others  :  https://smartech.gatech.edu/bitstream/1853/7645/1/song_qing_200512_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

Size and Shape Controlled Synthesis and Superparamagnetic Properties of Spinel Ferrites Nanocrystals Qing Song216 pagesDirected by Dr. Z. John ZhangThe correlationship between magnetic properties and magnetic couplings is established through the investigations of various cubic spinel ferrite nanocrystals. The results of this thesis contribute to the knowledge of size and shape controlled synthesis of various spinel ferrites and core shell architectured nanocrystals as well as the nanomagnetism in spinel ferrites by systematically investigating the effects of spinorbital coupling, magnetocrystalline anisotropy, exchange coupling, shape and surface anisotropy upon superparamagnetic properties of spinel ferrite nanocrystals. A general synthetic method is developed for size and shape control of metal oxide nanocrystals. The size and shape dependent superparamagnetic properties are discussed. The relationship between spinorbital coupling and magnetocrystalline anisotropy is studied comparatively on variable sizes of spherical CoFe2O4 and Fe3O4 nanocrystals. It also addresses the effect of exchange coupling between magnetic hard phase and soft phase upon magnetic properties in core shell structured spinel ferrite nanocrystals. The role of anisotropic shapes of nanocrystals upon self assembled orientation ordered superstructures are investigated. The effect of thermal stability of molecular precursors upon size controlled synthesis of MnFe2O4 nanocrystals and the size dependent superparamagnetic properties are described.