ISSN:0370-1972    

DOI:10.1002/pssb.2221910227

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221910228

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221910229

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe dependence of the mean atomic volumeVaof chalcogenide glasses belonging to the GexIn6Se94−xand GexIn12Se88−xfamilies of the Ge‐In‐Se system, on the average coordination number Z is investigated. TheVa‐Z plots for both families display maxima atZ= 2.75 and 2.83 corresponding to the tie‐line composition in In6and In12families, respectively. TheVa‐Zdependence for the In6family exhibits a minimum atZ= 2.54 and a broad local maximum atZ= 2.67, and that of the In12family shows a marked change in slope atZ= 2.50. These results are discussed in the framework of the chemically ordered covalent network model, Tanaka's model of topological transition, and the Phillips‐Thorpe model of rigid

ISSN:0370-1972    

DOI:10.1002/pssb.2221910202

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractSelf‐interstitial configurations in Fe are simulated using an embedded‐atom‐method (EAM) interatomic potential and an embedded‐defect (ED) one recently developed by the authors. The latter potential includes angular‐dependent many‐body local terms. Formation energy and lattice distortion for the 〈110〉 and 〈111〉 oriented dumbbells are calculated. The relative contributions of the pair and many‐body interaction terms to these properties are discussed. Comparisons with other many‐body potentials from

ISSN:0370-1972    

DOI:10.1002/pssb.2221910203

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe atomic structure of the (10 1 2) twin boundary in zinc is investigated theoretically by atomistic calculations and experimentally by high resolution electron microscopy. For computer simulations, the atomic interactions are described by a many‐body potential of the Finnis‐Sinclair type and are applied to a h.c.p. structure with a largec/a_ratio (1.856). Using this potential, only one planar atomic structure is found to exist for the (10 1 2) twin. This is in agreement with the previous results for h.c.p. metals withc/aratio close to the ideal value (1.633). In contrast, two atomic structures are observed experimentally: a planar and symmetric interface similar to the one obtained by calculations, and a microfaceted structure. The microfaceted structure is observed for the first time in the (10 1 2) t

ISSN:0370-1972    

DOI:10.1002/pssb.2221910204

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe concentrations of various atomic defects are calculated within the framework of a grand canonical formalism for the ordered compound FexAl1−xwith B2 structure as functions of temperature and composition. The input parameters for the grand canonical formalism are determined by the ab‐initio mixed‐basis pseudopotential theory in local‐density approximation. It is shown that FexAl1−xis neither a compound with pure antisite disorder nor a compound with pure triple‐defect disorder but that it exhibits a hybrid behaviour in which vacancies on the Fe sublattice and antisite atoms on both sublattices appear. The concentration of vacancies on the Al sublattice is negligibly small. The implications of this result for the modelling of diffusion mechanisms in FexAl1−x

ISSN:0370-1972    

DOI:10.1002/pssb.2221910205

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractTemperature and pressure dependence of thermal expansion and compression of alkaline earth oxides and cesium halides with NaCl‐ and CsCl‐type structures is investigated. The theory of interionic potentials based on the quantum mechanical form of the overlap repulsive energy is used to investigate the interatomic separations as a function of temperature and pressure from room temperature up to the melting temperature and from zero pressure up to the structural transition pressure. The values of van der Waals dipole‐dipole and dipole‐quadrupole energies are also included in the model. The results are used to predict the temperature and pressure dependence of the coefficient of volume thermal expansion using a formula derived on the basis of the thermodynamic analysis. The results are compared with available experimental data and discussed in the light of recent r

ISSN:0370-1972    

DOI:10.1002/pssb.2221910206

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractCorrelations between the Szigeti charge and the difference in phase volume in the alkali halides are presented. It is shown that the lattice bonding is enhanced if an alkali halide shows a bigger fractional change in volume at melting. The fractional change in volume for RbF can be obtained by extrapolation.

ISSN:0370-1972    

DOI:10.1002/pssb.2221910207

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractThe eigenfunctions and eigenenergies of an electron in a finite‐barrier cylindrical quantum wire are obtained. The case of different electron band masses in the cylinder and the barrier material is discussed. The polaron binding energy and the polaron effective mass due to the interaction of an electron with two cylindrical‐interface optical modes as well as with cylindrical bulk‐in and cylindrical bulk‐out confined LO‐phonon modes are calculated, and their dependence on the radius of the cylinder is studied in detail. The comparison with the results for a 2D polaron is

ISSN:0370-1972    

DOI:10.1002/pssb.2221910208

出版商:WILEY‐VCH Verlag    

年代:1995

数据来源: WILEY