Some NMR studies of NbSe₂

• Main Author: Abdolall, Khaled
• Language: English
• Published: 2010
• Subjects: Nuclear magnetism; Niobium selenide
• Online Access: http://hdl.handle.net/2429/18675

A sensitive nuclear magnetic resonance spectrometer has been constructed using Field Effect Transistors in a Robinson configuration. The spectrometer has been used to study the anomalous nuclear magnetic resonance spectra of single crystals of NbSe₂. An analysis of the field dependence of the line width in the low temperature phase has demonstrated that this results from a distribution of Knight Shifts. Such a distribution is not consistent with a structural transformation involving only two nonequivalent sites as proposed by Ehrenfreund et al. In addition accurate measurements of the Knight Shift and electric field gradient tensor have been made in the high temperature phase at 77K and 300K. The Knight Shift has a very large anisotropic component but an almost zero isotropic component which is indicative of negligible s-electron character at the: Fermi surface. === Science, Faculty of === Physics and Astronomy, Department of === Graduate