Further applications of magnetic resonance

• Main Author: Hayes, William
• Published: University of Oxford 1959
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.734652

The electron and nuclear magnetic resonance techniques are now well established and are extensively applied to the investigation of the solid state. We are at present largely concerned with the investigation of defect sites in ionic crystals which are associated with unpaired electronic spins. Phosphor and semiconductor physics are concerned in many instances with the behaviour of an impurity ion in a host lattice. An impurity cation will, in general, enter a host lattice substitutionally and in some cases may cause distortion of the lattice. Charge compensation must occur when the charge on the impurity cation and the host cation are not the same and the mechanics by which this is achieved is of interest. Accurate information about the behaviour of paramagnetic impurities may be obtained from the resonance spectrum. Many irradiation induced defects in alkali halides are paramagnetic and may be investigated by the electron resonance technique; addition of impurities extends the range of irradiation induced defects which may be produced. The stability of irradiation centres is temperature dependent and the variety of centres is enhanced by irradiation at low temperature. The nuclear magnetic resonance technique may be used to determine non-nuclear properties of materials. We are concerned here with magnetic interactions in paramagnetic iron group fluorides using the fluorine nucleus as a probe. The techniques which have been used to detect electron and nuclear magnetic resonance are outlined.