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Spin-dependent transport in magnetic tunnel junctions and diluted magnetic semiconductorsWang, Weigang. January 2009 (has links)
Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisor: John Q. Xiao, Dept. of Physics and Astronomy. Includes bibliographical references.
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Data recovery from magnetic media using magnetic force microscopyFerrett, Terry R. January 1900 (has links)
Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains x, 81, 9 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 73-75).
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Development of constant-time correlated spectroscopy on a 3T clinical MRI/MRS scannerAinala, Srilatha. January 1900 (has links)
Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains viii, 78 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 75-78).
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Nuclear magnetic resonance force microscopy adiabaticity, external field effects, and demonstration of magnet-on-oscillator detection with sub-micron resolution /Miller, Casey William, Markert, John T., January 2003 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2003. / Supervisor: John T. Markert. Vita. Includes bibliographical references. Available also from UMI Company.
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Development of synthesis method for spinel ferrite magnetic nanoparticle and its superparamagnetic propertiesHan, Man Huon. January 2008 (has links)
Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2009. / Committee Chair: Z. John Zhang; Committee Member: Angus Wilkinson; Committee Member: C P Wong; Committee Member: E. Kent Barefield; Committee Member: Mostafa El-Sayed. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Perfluorooctyl bromide emulsions as In Vivo carriers for laser polarized 129Xe for Magnetic Resonance imaging : the effect of phosphatidylcholine chain-leghth and oxygenation of the emulsion on longitudinal relaxation time (T1) and line-with /McPhee, Daniel P. January 1900 (has links)
Thesis (M. Sc.)--Carleton University, 2001. / Includes bibliographical references (p. 77-81). Also available in electronic format on the Internet.
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Nuclear magnetic resonance force microscopy of ammonium dihydrogen phosphate and magnetism of cobalt nanocrystalsMirsaidov, Utkur, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.
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Applications of magnetic resonanceBell, J. D. January 1967 (has links)
No description available.
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Spectroscopic and magnetic properties of pyridine and pyrazine complexes of divalent iron and copperHaynes, John Stephen January 1985 (has links)
Magneto-structural correlations have been made for a number of pyridine and pyrazine complexes of iron(II) and copper(Il), involving anions of a range of coordinating abilities, for example, sulfonate, RS0₃⁻ (where R is CF₃, CH₃ or p-CH₃C₆H₄); halide, Cl⁻ Br⁻ or I⁻; pseudohalide, NCO⁻ or NCS⁻; perchlorate and hexafluoroarsenate. Structure was determined by infrared, electronic and Mössbauer spectroscopy and differential scanning calorimetry, and, in some instances, by single-crystal X-ray diffraction. Spectroscopic results were used to investigate the nature of both anion and neutral ligand coordination.
In complexes of stoichiometry ML₄ (RS0₃)₂ (where M is Fe or Cu, L is pyridine, pyrazine or 2-methylpyrazine and R is CF₃, CH₃ or p-CH₃C₆H₄), the neutral ligands were found to adopt a unidentate mode of coordination. For several of these complexes, X-ray crystallography revealed a square-planar array of pyridine ligands around the central metal, with anions coordinated in a unidentate mode above and below this plane. A monomeric molecular structure results in which the paramagnetic centres are well isolated from each other giving rise to magnetically-dilute species.
In complexes of stoichiometry M(pyz)₂X₂ (where M is Fe or Cu and X⁻ is CF₃S0₃⁻, CH₃S0₃⁻, Cl⁻, Br⁻, I⁻, C10₄⁻ or NCS⁻), pyrazine was found to coordinate through both nitrogen donor atoms and inorganic coordination polymers were produced. X-ray crystallography revealed a two-dimensional lattice in Cu(pyz)₂(CH₃S0₃)₂ with two distinct kinds of bridging pyrazine groups and monodentate sulfonate anions. For the remaining bis(pyrazine) complexes, spectroscopic evidence supports similar structures with unidentate anion coordination and bidentate
bridging pyrazine ligands leading to sheet-like polymers. Cu(pyz)₂(CH₃S0₃)₂ and Fe(pyz)₂(NCS)₂ exhibit magnetic susceptibilities which reveal the antiferromagnetic nature of these materials (ˣmax at temperatures of 7.0 and 8.0 K respectively); the data were analysed in terms of a two-dimensional Heisenberg model. For the copper complex, in which the structure shows stronger pyrazine coordination along one dimension, the data were also analysed in terms of a linear chain model. Mössbauer spectroscopy showed Fe(pyz)₂(NCS)₂ to undergo a transition to a magnetically-ordered state at 9.2 K. The magnitude of the exchange coupling through bridging pyrazine in Fe(pyz)₂X₂ complexes (where X⁻ is CF₃S0₃⁻, CH₃S0₃⁻, Cl⁻, Br⁻, I⁻ or C10₄⁻) is considerably less than that present in either Cu(pyz)₂(CH₃SO₃)₂ or Fe(pyz)₂(NCS)₂.
Spectroscopic evidence indicates that for Fe(py)₂(CF₃S0₃)₂ and complexes of stoichiometry M(pyz)X₂ (where M is Fe or Cu and X⁻ is CF₃S0₃⁻, p-CH₃C₆H₄S0₃⁻, Cl⁻ or NCO⁻) bridging anionic ligands are present and for the mono(pyrazine) complexes the neutral ligand also coordinates in a bridging mode. Fe(pyz)(CF₃S0₃)₂, Fe(pyz)(NCO)₂ and Cu(pyz)(CF₃SO₃)₂ all exhibit magnetic susceptibility data characteristic of antiferromagnetic materials (ˣmax at temperatures of 4.4, 38 and 7.0 K respectively). The magnetic susceptibilities for these materials were analysed in terms of the two-dimensional Heisenberg model and a linear chain model. Mössbauer spectroscopy shows both Fe(pyz)(CF₃S0₃)₂ and Fe(pyz)(NCO)₂ to undergo a transition to long-range magnetic ordering at temperatures of 3.9 and 27.0 K respectively.
Low-temperature (4.2-130 K) magnetic susceptibility measurements for the iron(II) sulfonate compounds, Fe(RS0₃)₂ (where R is F, CF₃, CH₃ or p-CH₃C₆H₄) are reported. For the compounds where R is F, CF₃ or p-CH₃C₆H₄ the magnetic moment data were assessed in terms of crystal-field splitting effects. The magnetic moment data for ɑ and β forms of Fe(CH₃S0₃)₂ are indicative of antiferromagnetic exchange interactions and the characteristics of the susceptibility curve for the β isomer are explained on the basis of a transition from short-range to long range three-dimensional magnetic ordering at 22 K. / Science, Faculty of / Chemistry, Department of / Graduate
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Aspects of NMR imaging and in vivo spectroscopyTalagala, Sardha Lalith January 1986 (has links)
The work described in this thesis deals mainly with aspects related to two- and three-dimensional NMR imaging.
A detailed discussion on frequency-selective excitation using amplitude modulated rf pulses in relation to slice selection in NMR imaging has been presented. This includes the analysis and implementation
of the method as well as illustrative experimental results.
Several radiofrequency probe designs suitable for high field NMR imaging have been experimentally evaluated and their modification and construction are also described. The comparative results obtained indicate the merits and demerits of different designs and provide necessary guidelines for selecting the most suitable design depending on the application.
Practical aspects of two- and three-dimensional imaging have been discussed and NMR images of several intact systems have been presented.
Experimental methods which enable slice selection in the presence of chemically shifted species and two-dimensional chemical shift resolved imaging have "been described and illustrated using phantoms. The use of three-dimensional chemical shift resolved imaging as a potential method to map the pH and temperature distribution within an object has also been demonstrated.
A preliminary investigation of the application of ³¹P NMR spectroscopy
to study the biochemical transformations of the rat kidney during periods of ischemia and reperfusion has been presented. / Science, Faculty of / Chemistry, Department of / Graduate
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