[en] The set-up for complex solid state spectroscopy with the use of enhanced properties of radiation from insertion devices and free electron lasers is proposed. Very high flux and pulsed properties of radiation from insertion devices and free electron lasers offer the possibility for the use of such powerful techniques as electron paramagnetic resonance (EPR) and optically detected magnetic resonance (ODMR) for the studies of excited states of electronic excitations or defects in solids. The power density of radiation can become high enough for one more method of exited-state spectroscopy: transient optical absorption spectroscopy. The set-up is supposed to combine the EPR/ODMR spectrometer, i.e. cryostat supplied with superconducting magnet and microwave system, and the optical channels for excitation (by radiation from insertion devices or free electron laser) and detection of luminescence (i.e. primary and secondary monochromators). The set-up can be used both for 'conventional' spectroscopy of solids (reflection and absorption spectroscopy, time-resolved luminescence spectroscopy, photon stimulated desorption) and as EPR/ODMR spectrometer

[en] A quantitative diagram of the energy band structure is constructed according to the method of pseudopotential with correction in experimental reflection spectra of BeO monocrystal cleavage in the fundamental region of the spectrum. Comparison of the known theoretical data with experimental ones is given

[en] Optical properties of MgO monocrystal are investigated experimentally and theoretically. Eelectron zone structure of MgO is calculated self-consistently by the associated plane wave technique in terms of local approximation for exchange-correlation effects in the electron density functional theory. The experiment was conducted using synchronous radiation. Calculation of optical spectrum was carried out by Kramers-Kronig correlations. It is determined that MgO is a direct-zonal dielectric with certain covalence of correlation. The main peculiarities of optical spectrum are explained in the paper, as well

[en] The spectra are measured of 5.3 eV luminescence recombination luminescence for MgO - Al crystals excited by 5 - 170 eV synchrotron radiation. Thresholds of the multiplication effect of electron-hole pairs (19.5, 31, 42 eV) that is related to the formation of secondary, ternartiary, etc. electron-hole pairs by fast primary electrons are determined using the data on reflection (absorption) spectra and external photoelectric effect. The phenomenological model is conducted taking into account the quantum yield dependence on the initial electron-hole separation, the near-surface nonradiative recombinations, and the presence of cation electron excitations of 53.7, 57.7, 59.8, 64.2 eV in MgO

[en] A high-luminosity system comprising optically matched sample chamber, monochromator-spectrograph, and detectors of luminescences has been designed for XEOL spectroscopy using synchrotron radiation. Exciting x-ray radiation penetrated the sample chamber through a window made of a Be foil. The sample is mounted on the sample holder of a nitrogen cryostat. The entrance slit of the monochromator is fixed on the sample's surface. Luminescence is excited and detected at the same side of the sample and optical slit; the angle between the exciting radiation and the entrance shoulder of the monochromator is 45 degree. Sample chamber has two windows made of a Be foil for incident and transmitted x-ray radiation and another one made of MgF₂ for outcoming luminescence. A Seya--Namioka mounting with 70.5 degree has been chosen for the spectra instrument as it is characterized by a flat field in the focal surface in the area of the exit slit, providing the possibility to detect luminescence either in the mode of a monochromator or a spectrograph. In the first case it is detected by a photomultiplier with a sodium salicylate screen or a mirror in front of it depending on the spectral range. In the spectrograph a photodetector array is applied. The switching of the modes is achieved by a mirror in front of the exit slit. Changeable diffraction gratings with radius 250 mm and density of grooves per mm 300 and 600 make the instrument efficient in the spectral range 110 to 1400 nm providing resolution up to 1 nm. The sample chamber and the monochromator are separated by a window made of MgF₂. Vacuum in the sample chamber is better than 10^-7 Torr, in the monochromator better than 10^-4 Torr. Temperature of the sample can be varied in the range 80--600 K. The level of the scattered light in the instrument is lower than 10^-4

No abstract available

[en] By the method of pseudopotential in a nonlocal approximation the dispersion of CdId₂ strongly anisotropic wide-band crystals is calculated. By optic reflection spectra obtained from synchrotron radiation, by the Kramers-Kronig method the real and imaginary parts of the dielectric permittivity have been calculated at 77 K. The CdId₂ crystals band structure is calculated and interband optical transitions by concrete points of the Brillouin zone are identified

[en] Here we present the results of the reflectivity and luminescence excitation measurements of a set of oriented crystals MeWO₄ (Me=Mg, Pb) demonstrating the polarization effects, when using linearly polarized synchrotron radiation (SR)

[en] Time-resolved luminescence as well as excitation and reflectivity spectra of the oriented lead and barium molybdate single crystals were studied using synchrotron radiation. Features in reflectivity spectra in the fundamental absorption region were analyzed. The contribution of electronic states of lead cation to the formation of the bandgap in PbMoO₄ is supposed. The role of lead states in the intrinsic luminescence of PbMoO₄ is discussed

No abstract available