Zenon Bochyński

X-ray diffraction studies of molecular correlations in liquid phenylcyclohexane

Abstract This paper reports results of the X-ray diffraction using CuK α radiation of liquid phenylcyclohexane at room temperature. An angular distribution of X-ray scattered intensity was measured. The electron-density radial-distribution function was numerically found using Fourier analysis. Structural parameters, the mean distances between the neighbouring molecules and the mean coordination numbers were found. A simple model of local arrangement of the molecules in liquid phenylcyclohexane was proposed.

Surface and near-surface structure of silicate glasses

Abstract This paper presents analytic results, derived by diffractional low and large angle X-ray scattering methods, currently applied in our laboratory, as well as novel methods of electron emission microscopy and interference-phase optical microscopy for studying the internal structure, and that of surface and near-surface layers of raw and stepwise-etched, composite oxide silicate glasses of the type SiO 2 -Na 2 O-CaO-MgO. The structural and topographic studies are supplemented with quantitative analysis of chemical composition on a micro-scale and in micro-regions by electron microprobe and microscopic measurements of the temperature characteristics in a series of the above glasses. Moreover, a discussion is given of chemical corrosion, surface strcuture and topography, and the distribution of micro and macro-inhomogeneity regions in surface layers. Structural parameters are obtained which described the surface and internal structure of silicate glasses well adapted to the construction of an approximate aperiodic nodal model. The applications of the latter and the accuracy of its parameters are discussed.

Optical microscopic mapping of the domain structure of BaTiO3 microcrystals

Abstract The studies of 90° and 180° domain structure in a series of thin and ultrathin BaTiO3 microcrystals have been performed. The effects of thermal, electric and mechanical treatment on the processes of ageing and memory of the domain structure have been analysed. The studies were carried out in the region of the temperature phase transition in a constant electric external field and under point or linear mechanical stress. The applied methods of analysis were optical microscopy and X-ray diffraction. The relations between the domain and crystalline structure of the microcrystals were discussed in the whole range of thermal, electric and mechanical transformations.

X-ray Scattering in Liquid Pentane

Abstract X-ray diffraction investigation of liquid n-pentane CH3—(CH2)3—CH3 was performed at 293 K. An angular distribution of X-ray scattered intensity was measured by applying MoK α (γ = 0.71069 Å) radiation. The electron density radial distribution function was numerically found using Fourier analysis. The mean distances between the neighbouring atoms were found. A simple model of short-range arrangement of the molecules was proposed.

Internal and surface layer structural analysis of silicate glasses

Abstract This work is on the internal and surface layer structures of sodium-silicate glasses and silica gels. Structural parameters are determined by low and high angle X-ray scattering methods. The correctness of the new analytical method used for components of silica gels and silica glass is checked and then the method is successfully applied to sodium-silicate glasses. By substracting adequate functions of radical distributions and by successive approximations of the effective molecule, by the addition of succesiive oxide groups (Na 2 O, CaO, and MgO) parameters enabling the design of oxide glass nodal model are determined.

Model of short-range order in liquid bicyclohexyl from x-ray diffraction studies

Abstract The structure of liquid bicyclohexyl, C 6 H 11 - C 6 H 11 at 293 K was investigated using the X-ray diffraction method. Monochromatic radiation CuK α enabled one to determine the scattered radiation intensity between S 0 = 4π sin ϑ 0 /λ = 0.417 A −1 and S max = 7.06 A −1 . The angular distribution of X-ray radiation scattered was measured, and electron-density radial-distribution function (EDRDF) was numerically found using Fourier analysis. A good agreement between the theoretical and experimental functions was obtained on assuming the statistically most probable model of this molecule. The structural data obtainable by X-ray analysis for liquid bicyclohexyl were discussed. The mean distances between the neighbouring molecules were found. The maxima in the EDRDF were at : r 1 = 4.68 , r 2 = 5.57 , r 3 = 6.62 , r 4 = 8.05 A . Computer techniques were used to minimize the effects of experimental errors, uncertainties in the scattering factors, and termination errors. X-ray structural analysis was applied to determine the packing coefficient of bicyclohexyl molecules. A simple model of short-range arrangement of the molecules in liquid bicyclohexyl was proposed.

The effect of temperature and electric field on domain structure of BaTiO3

Abstract The paper present the results of investigation of the crystal structure of BaTiO3 ceramics and monocrystals as well as the structure of 90° and 180° domains.

Short-range ordering in liquid bicyclohexyl by X-ray diffraction

Abstract The paper reports results of the X-ray diffraction structural studies of liquid bicyclohexyl, C6H11—C6H11 at room temperature, using CuK α radiation. Angular distribution of X-ray scattered intensity was measured, and the electron-density radial-distribution function was calculated. Computer techniques were used to minimize the effects of experimental errors, uncertainties in the scattering factors, and termination errors. Good agreement between the theoretical and experimental functions was obtained on assuming the statistically most probable model of this molecule. The structural data obtainable by X-ray analysis for liquid bicyclohexyl were discussed. The mean distances between the neighbouring molecules and the radii of coordination spheres were found. The maxima in the differential radial distribution function were at: r 1 = 4.68, r 2 = 5.57, r 3 = 6.62, r 4 = 8.05 Å. X-ray structural analysis was applied to determine the packing coefficient of bicyclohexyl molecules. A simple model of short-range arrangement of the molecules in liquid bicyclohexyl was proposed.

New methods of determining the real structure parameters of special gels and silicate glasses

Abstract This paper is concerned with the application of new x-ray diffraction methods for studying the structure of gels and silicate glasses. Low- and wide-angle x-ray diffraction methods were applied. The summarized, differential and differentiated by subtraction radial distribution functions were analyzed. Basic structural parameters (interatomic distances, distances between groups of atoms and coordination numbers and zones) internal ordering degree and concentrations of inhomogeneous zones were determined. Structural models approximating the real structure of special gels (SiO 2 ·xH 2 O and SiO 2 ·xH 2 O + R 2 O 3 ) and models of local ordering in silicate glasses (SiO 2 , SiO 2 + Na 2 O 3 + CaO + MgO + R 2 O 3 /FeO, Fe 2 O 3 ) are also described. The theory of the structural analysis applied to the materials studied is presented, including a detailed description of the new methods used to determine the parameters of the real structure of the substances studied. The usefulness of the measuring and analysis methods is described also. A comparison is made between data obtained in my laboratory and that available in the literature. The structural models constructed from the structural parameters obtained by the radial function method are considered as to their accuracy and probability to be found. The accuracy of the measurements, both apparatus and numerical calculations, is evaluated. The structural diffraction measurements are supplemented with the analyses of surface layers made by other methods including x-ray spectrometry and microspectrometry, emission electron microscopy, and local microhardness and microplasticity.