Spin dynamics of pulsed nuclear magnetic double resonance in solids

• Main Author: Stoll, Michael Edward
• Format: Others
• Published: 1977
• Online Access: https://thesis.library.caltech.edu/8579/2/Stoll%201977.pdf; Stoll, Michael Edward (1977) Spin dynamics of pulsed nuclear magnetic double resonance in solids. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/3A2F-RM03. https://resolver.caltech.edu/CaltechTHESIS:07212014-160352901 <https://resolver.caltech.edu/CaltechTHESIS:07212014-160352901>

<p>In the first part of this thesis, experiments utilizing an NMR phase interferometric concept are presented. The spinor character of two-level systems is explicitly demonstrated by using this concept. Following this is the presentation of an experiment which uses this same idea to measure relaxation times of off-diagonal density matrix elements corresponding to magnetic-dipole-forbidden transitions in a ^(13)C-^1H, AX spin system. The theoretical background for these experiments and the spin dynamics of the interferometry are discussed also. </p> <p>The second part of this thesis deals with NMR dipolar modulated chemical shift spectroscopy, with which internuclear bond lengths and bond angles with respect to the chemical shift principal axis frame are determined from polycrystalline samples. Experiments using benzene and calcium formate verify the validity of the technique in heteronuclear (^(13)C-^1H) systems. Similar experiments on powdered trichloroacetic acid confirm the validity in homonuclear (^1H- ^1H) systems. The theory and spin dynamics are explored in detail, and the effects of a number of multiple pulse sequences are discussed. </p> <p>The last part deals with an experiment measuring the ^(13)C chemical shift tensor in K_2Pt(CN)_4Br_(0.3) • 3H_2O, a one-dimensional conductor. The ^(13)C spectra are strongly affected by ^(14)N quadrupolar interactions via the ^(13)C - ^(14)N dipolar interaction. Single crystal rotation spectra are shown. </p> <p>An appendix discussing the design, construction, and performance of a single-coil double resonance NMR sample probe is included. </p>