The preparation and spectroscopic investigation of mono- and polycrystalline paramagnetic materials.

A number of crystalline compounds with widely different physical properties were prepared using several techniques of crystal growth. The techniques included growth from solution, from the flux, from the melt, and from the vapour. A zone-refiner, in addition to purifying materials, was also used to prepare single crystal fragments. The materials prepared by these techniques were irradiated with gamma-rays or neutrons, and the resulting paramagnetic centres were investigated by electron spin resonance spectroscopy. Radicals were examined in sodium cyanide, potassium sulphate, potassium chromate, potassium fluorochromate, calcium molybdate doped with neodymium tantalate, and magnesium oxide doped with fluoride ions.