Diamond single crystals showing Infra-red features of pressurized CO2-I phase were studied using Transmission Electron Microscopy (TEM) and tomography. Numerous O-containing precipitates with sizes up to 45 nm are observed. The absolute majority these decorate dislocation loops or located inside them; individual scattered also present. Morphology the varies from quasi-isometric octahedra highly...

Fine structure of ground electron state Fe4+ impurity ion in a natural amethyst crystal was studied by broadband paramagnetic resonance spectroscopy the frequency range 34–500 GHz. It is established that energy levels scheme consists quasi-doublet Sz = ± 2, S z= 1 and singlet Sz=0 with zero-field energies 4.9 GHz, 435.2 45.4 GHz 584 respectively. Parameters effective spin Hamiltonian describing...

We show that in cubic crystals with anisotropic impurity centers the sum of squares magnetic resonance [electron paramagnetic (EPR)] frequencies is invariant respect to field direction. The connection between such an and $g$-tensor components derived for different types centers. established regularity confirmed experimentally spin-noise spectra a $\mathrm{Ca}{\mathrm{F}}_{2}\ensuremath{-}{\math...

Detailed studies of emission and excitation spectra impurity Ho3+ centers in the SrY2O4 single crystal performed by means site-selective laser spectroscopy are reported. The energy levels patterns for 5I8, 5I7, 5I6, 5S2 5F4 multiplets ions which substitute Y3+ at two structurally nonequivalent sites Y1 Y2 with local Cs symmetry constructed making use measured spectra. These schemes well describ...

Theory of the off-centre instability is developed for the impurity ions (Li', CuC, and Ag') in alkali halides on the basis of the charge transfer excitation model which is different in the involved electronic processes from the earlier theory based on the polarizable-point charge ion model. The lowest potential minima for the impurity ion along < 11 1 ), ( 110 ), and < 100 ) crystal axes are ca...