Vorona I. Electron-nuclear double resonance of dangling bonds in non-metal solids

The dissertation is devoted to study of the ENDOR of dangling bonds in porous silicon, tooth enamel and fullerite С60. The general properties and distinctive features of these centers and their ENDOR signals in different matrix are found. Resonance lines are centered about nuclear Larmor frequencies and caused by crystalline, matrix and powder types of ENDOR. The study of crystalline ENDOR signals in porous silicon allows to define the SHF constants of Pb-centers with protons interacting with dangling bonds and to clarify the model of this center. The analyses of powder ENDOR spectra in irradiated tooth enamel permits to define SHF constants of СО2- radical with phosphorus and hydrogen nuclei and to determine the radical location in bioapatite lattice. The study of ENDOR in fullerite has shown that its dangling bonds interact with hydrogen nuclei similar to porous silicon. These protons are at a distance about r = 10 A from defect. The correlation between ENDOR linewidth, microwave power and concentrat ion of dangling bonds has been found. A new method of EPR dosimetry based on EPR imaging permitting to define irradiation type has been proposed.