摘要:

AbstractSilane decomposition and silicon layer growth will be described by way of theory taking into account heterogeneous as well as homogeneous reaction mode and 1st as well as 0.5th order of the chemical reaction. Comparing axial layer growth rate distribution and total substrate surface area effect on the latter with respect to theoretical and experimental results (for the process conditions investigated), it will be shown that the deposition of undoped poly silicon is characterized by a heterogeneous reaction mode, whereas chemical reaction is of first reaction order in the temperature range above 973 K and of 0.5th reaction order below 973 K. The deposition kinetics of strongly in‐situ phosphorus doped poly silicon is shown to be in agreement with a homogeneous reaction mode of 0.56threaction orde

ISSN:0232-1300    

DOI:10.1002/crat.2170280108

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractThe mechanically induced changes in structure and magnetic properties of zinc ferrite were investigated by using the Rietveld analysis and Mössbauer spectroscopy. The formation of the spin arrangement in mechanically activated zinc ferrite is connected with a redistribution of the cations in the close‐packed anionic sublattice. On the basis of the Rietveld analysis the degree of mechanically induced inversion as well as the exact coordinates of atoms and lattice parameters in non‐activated and mechanically activated ZnFe2O4was determ

ISSN:0232-1300    

DOI:10.1002/crat.2170280109

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractExperimental and literature informations on the phase equilibria f.c.c. solid/liquid CoZn solutions, and about the thermodynamic properties of these alloys have been combined for the evaluation of two sets of polynomial coefficients serving to calculate thermodynamic or phase boundary value

ISSN:0232-1300    

DOI:10.1002/crat.2170280110

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractThe decomposition behaviour of two AlSc alloys (cSc= 0.18; 0.36 at.%) after direct quench to room temperature and subsequent ageing at temperatures in the range 200 °C ≦Ta≦ 550 °C was investigated by means of isothermal resistivity measurements and TEM. In the temperature range 325 °C ≦Ta≦ 400 °C both alloys show independent of the Sc content an “inversion” of the decomposition kinetics, obviously caused by the transition of the coherent into the incoher

ISSN:0232-1300    

DOI:10.1002/crat.2170280111

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractTheoretical relations are derived for the amplitude of the photoacoustic signal of a gas‐coupled cell for thick semiconductor samples including the influence of multiple reflections of light within the sample. It is shown that in the range of low absorption coefficients characteristic of impurity absorption spectra the sensitivity of the cell can be enhanced by using a highly reflecting metal as backing material. Numerical estimates for CuInSe2are given to illustrate this effec

ISSN:0232-1300    

DOI:10.1002/crat.2170280112

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractOptical absorption spectra of n‐type CuInSe2single crystals were evaluated by means of photoacoustic spectroscopy in the photon energy range from 0.94 to 1.02 eV. At photon energies below 0.99 eV the spectra exhibit exponential tails that are ascribed to the presence of shallow impurity states. At higher photon energies the absorption coefficients follow the relation for direct allowed optical transitions between parabolic bands. The parameters of this relation are determined and compared with previous measurement

ISSN:0232-1300    

DOI:10.1002/crat.2170280113

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractSome halogen‐doped calcium borate glasses containing iron have been prepared according to the percentage molar composition [(30 –x) CaO ·xCaX2· 10 Fe2O3· 60 B2O3] and annealed. It is found that the conduction in the semiconducting glasses is mainly due to electronic conduction. The results show that the halide ions may be introduced as modifiers for CaX2concentration10 mol%. It is proposed that at 10 mol% the network structure for all glasses seems to be the same. The dependence of resistivity on the halide ions concentration as well as the slight variation of activation energies, could be explained on the basis of electron‐lattice interaction.Mathematical expressions for fitting and describing the dependence of resistivity on CaX2concentration are deduced and formulated by the following equations: ϱ = ϱ0exp [±ac(1 –bc)] and ϱ ϱ= ±10exp [±a′c(1 –b′c)] for the two regions around the

ISSN:0232-1300    

DOI:10.1002/crat.2170280114

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractIonic conductivity measurements have been made on Potassium Chloride crystals doped with different concentrations of Yttrium, in the temperature range 200 °C to 600 °C, to understand the nature of impurity vacancy (I–V) complexes, various types of their formation and to understand how these I–V complexes affect the conduction process. The conductivity‐temperature plots of KCl: Y showed three distinct regions. These regions are explained on the basis of Dryfus and Nowick notation, formation and dissociation of yttrium impurity preci

ISSN:0232-1300    

DOI:10.1002/crat.2170280115

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractThe effects of quenching temperature and orientation of Knoop indenter on microhardness of cleavage planes of synthetic sodium nitrate crystals are studied for the range of applied loads (20–160 g) in the high load region. Phenomenological approach was followed to obtain an empirical relation connecting Knoop hardness number, orientation, and quenching temperature. Anisotropic indices are also determined. The implications are discusse

ISSN:0232-1300    

DOI:10.1002/crat.2170280116

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY

ISSN:0232-1300    

DOI:10.1002/crat.2170280117

出版商:WILEY‐VCH Verlag    

年代:1993

数据来源: WILEY