Thermally Stimulated Discharge Current Studies in Thin Films of Polyacrylamide

TSDC of pure polyacrylamide films of thickness 22 μ grown by isothermal solution growth technique has been studied as a function of polarizing field and polarizing temperature at a constant heating rate of 0.09 K s¹ In these studies only one TSDC peak was observed and the temperature corresponding to this peak was found to be independent of polarizing field strength but dependent on polarizing temperature. The activation energies, relaxation parameters and charge associated with the peak were evaluated. The origin of TSDC is discussed.     

Synthesis and Characterization of the Levyne-like Structure SAPO-35, Prepared with Cyclohexylamine as Templating Agent

The microporous aluminophosphate SAPO-35 with the levyne-like structure was prepared hitherto only with quinuclidine as templating agent. In this paper it is shown that also cyclohexylamine can be used for the synthesis of SAPO-35. The samples were characterized by X-ray diffraction, thermal analysis, adsorption isotherms, and micrographs. These investigations confirm the few data reported on SAPO-35 and give further informations. The number of acid sites (Brönstedt centres) was determined from the differential molar heat of chemisorption of NH₃ to three per unit cell.     

Investigation of the Interaction of Quartz with Hydrogen under Supply of Mechanical Energy (II) Investigation by IR Spectroscopy

Infrared investigations demonstrate a chemical interaction of quartz in hydrogen atmosphere during mechanical activation: By means of the SiH stretching band the number of formed SiH-groups is estimated as a function of the period of activation. of activation. This number is more than one order of magnitude less than the total number of adsorbed molecules.     

X-ray and X-ray photoelectron spectra of vanadium oxides

X-ray (XS) and X-ray photoelectron (XPS) spectra are reported for vanadium oxides. Because of the multivalent character of vanadium in the oxide system high quality measurements can be used for chemical shift investigation. Both inner level and valence band spectroscopy give information on the electronic structure and their systematic change with increasing oxidation state. The experimental results are discussed favourable in terms of molecular orbital theory (MO-theory). The complete set of XS and XPS data reported here for V-oxides allows the identification of unknown vanadium oxidation states too.     

A linear relativistic method for the calculation of band structure in transition metals with results for Au

With a linear relativistic method we calculated the band structure of gold. A comparison with the results of a RAPW calculation shows that the deviation is about 3%. The effort of computational time is for the linear method considerably smaller than for the RAPW method.     

X-ray determination of mean square amplitudes of lattice oscillations in compounds with ZnS structure

A general method of determination of the mean square amplitudes of lattice oscillations (MSA) for crystals with sphalerite structure is described and applied to InP. The linearity of suitable functions of the measured integral BRAGG intensities of sin² θ/λ² is used for the verification of the parameters selected for the correction of extinction and DTS. In this way the accuracy of the results is increased. The MSAs of the InP-sublattices are evaluated. According to theoretical expectations the MSAs of the P-sublattice are larger because of the greater contributions of optical phonons.