Properties of magnetization tunneling in high -spin molecules at low temperature.
Item
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Title
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Properties of magnetization tunneling in high -spin molecules at low temperature.
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Identifier
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AAI9997135
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identifier
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9997135
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Creator
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Zhong, Yicheng.
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Contributor
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Adviser: Myriam P. Sarachik
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Date
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2001
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Language
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English
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Publisher
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City University of New York.
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Subject
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Physics, Condensed Matter
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Abstract
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Based upon several interesting experiments, this thesis aims to address some deeper properties of Quantum Tunneling of Magnetization in Mn12 -acetate, a high-spin molecular magnet at low temperature. After a brief introduction (Chapter 1), I will show data obtained from Inelastic Neutron Scattering experiments in Mn12 revealing the presence of higher order uniaxial anisotropy (Chapter 2), a term central to the discussion of the results presented later. Chapter 3 will deal with a study of the magnetic relaxation of single crystals of Mn12 in the regime of thermally assisted tunneling; complex features were found within each resonance which are not fully understood at this time. In Chapter 4 I will describe a sensitive Hall bar technique for measuring the magnetization of micron-size samples at very low temperature. I will present experimental data of hysteresis obtained at temperatures down to 0.4 K in Mn12, and then interpret the data in light of the higher-order anisotropy and the theory of the first-order transition in Mn12. A separate study of the effect of a transverse magnetic field on the lineshape of the N = 0 resonance in Mn12 will be presented in Chapter 5. It will help further identify the unsolved key issues related to the tunneling mechanism in Mn12. I will conclude my dissertation with a summary and suggestions for future studies in Chapter 6.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
