acta physica slovaca

Abstract: In this communication we discuss SU(1,1) and SU(2) squeezing of an interacting system of radiation modes in a quadratic medium in the framework of Lie algebra. We show that regardless of which state being initially considered, squeezing can be periodically generated.

Abstract: The introduction of an upper limit to the proper acceleration of point-like particles may lead to new as well as interesting results in the particle production scheme of QFT in curved space-times. Some examples are discussed.

Abstract: We argue that self/anti-self charge conjugate states of the (1/2,0) (0,1/2) representation possess axial charges. Furthermore, we analyze recent claims of the interaction terms for ``fermions''. Finally, we briefly discuss the problem in the (1,0) (0,1) representation.

Abstract: In a U(3) x U(3) quark chiral model of the Nambu-Jona-Lasinio (NJL) type with the 't Hooft interaction, the ground scalar isoscalar mesons and a scalar glueball are described. The glueball (dilaton) is introduced into the effective meson Lagrangian written in a chirally symmetric form on the base of scale invariance. The singlet-octet mixing of scalar isoscalar mesons and their mixing with the glueball are taken into account. Mass spectra of the scalar mesons and glueball and their strong decays are described.

Abstract: Inclusive spectra of 197Au( ,t) and 197( ,3He) reactions at =50 MeV have been measured in a wide range of energies and angles. The results are compared with the exciton model coalescence and with the particle elastic break-up PWBA calculations. New mechanism of formation and consequently of the emission from states with different number of unbound particles is proposed to describe the complex particle emission in -induced reactions within the frame of the exciton model.

Abstract: Tin-doped indium oxide (ITO) films were deposited by means of DC-planar magnetron sputtering. A metallic In/Sn (90/10) target and an Ar/O2 gas mixture were used. The oxygen flow was varied between 0 and 2 sccm. Substrate voltages between 0 and -100 V were used. With increasing oxygen flow film structure and composition change from crystalline metallic In/Sn to amorphous ITO. Simultaneously the deposition rate decreases and the film density increases. The diffusion of oxygen into metallic In/Sn films and the amorphous-to-crystalline transformation of ITO were studied using in situ grazing incidence X-ray diffractometry (GIXRD), grazing incidence reflectometry (GIXR), and AFM. From the X-ray integral intensities diffusion constants, activation energies of the diffusion, reaction order and activation energy of the crystal growth process were extracted.

Abstract: Hot-filament chemical vapor deposition (HFCVD) method is presented to prepare i) free-standing diamond films using Si (100) mirror-polished substrate and ii) diamond coatings deposited on WC/Co cutting plates. Both diamond films and coatings have been prepared with high quality as has been shown an analysis by micro-Raman spectroscopy. Raman spectra also have showed similar structure for both deposited films and coatings, respectively. We have found the almost same of position of a luminescence peak in the diamond coating as in the free-standing diamond film. A method is proposed for evaluation of relatively concentration of luminescence centers in the film. A discussion is considered about structure of such centers.

Abstract: The effect of deposition temperature and N2 gas partial pressure on the morphology, structure, composition and electrical properties of CNx thin films was studied by HRTEM, EDS, STM and STS. Morphology ranging from homogeneous layers through spherical or cylindrical particles embedded into the films to low density globular deposit of CNx was observed as a function of the applied N2 gas pressure. The N-composition was found between 1-20% and the structure varied from amorphous through fulleren-like to nanocrystalline diamond composed with amorphous CNx depending on the temperature and the plasma parameters.

Abstract: Glass samples of composition 30mol% of P2O5 and 70mol% V2O5 were used in this study. They were prepared by the usual melt-quench method. The electrical conductance and capacitance were measured over the frequency range 1 Hz to 1 MHz. Measurements were performed in the temperature range between 303 and 403 K. The dielectric and complex impedance response of the measured structure is discussed. The equivalent circuit was proposed and its parameters calculated. A good agreement between proposed double-layer physical model and parameters of equivalent electrical circuit was obtained.