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Information × Registration Number 0200U001283, 0195U010995 , R & D reports Title Microwave spectroscopy of new and perspective materials popup.stage_title Head Ishchenko Stanislav Stepanovych, Registration Date 18-05-2000 Organization Institute of Semiconductor Physics popup.description2 The objects of the study are silicon and its oxide; porous silicon, fullerens and fullerites, SiC, biominerals, solid solutions, ferroelectrics, narrow-gap semiconductors. The purpose of study is to obtain new information about the intrinsic and impurity defects in perspective materials: to clarify the nature, energy and microstructure of centers, to determine their characteristics, to define mechanisms of their influence on properties of solid materials. The techniques of study are EPR, ENDOR, spin-relaxation measurements, MRI, Brilluen scattering, quantum-chemistry calculation. The dangling bonds in porous silicon, C60 fullerites and SiC, Si-nK centers in silicon, E', EP2 and EP3 centers in Si+- and Ge+-doped SiO2 layers, radiation-induced defects in bioapatite, impurity centers formed by elements of iron group and rare-earth ions in alkaly halide crystals, LiNbO3 and narrow-gap semiconductors, nitrogen centers in SiC were studied. The models of defects, their characteristics and localization in crys tal lattice, the constants of fine, hyperfine and exchange interactions, the formation mechanisms for different centers and influence of defects on material properties were clarified. The size phenomena in EPR spectra were studied. It was shown that the materials with predicted properties can be obtained by creation of definite type centers. The theory of EPR and PER in crystalline field of icosahedral symmetry which is characteristic for fullerens were developed. The theory of two-electron centers and bipolarons for a case of strong electron-phonon coupling in anisotropic crystals was derived. The procedure of EPR dosimetry with determination of irradiation type and method of creation of superconductive region in ferroelectric materials based on metal-oxide compounds were developed. Product Description popup.authors popup.nrat_date 2020-04-03 Close