ISSN:0370-1972    

DOI:10.1002/pssb.2221630141

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221630142

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221630143

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221630144

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221630145

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221630146

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractThe elastic interaction energy between a screw dislocation and a point defect is given in non‐local elasticity. The interaction energy has no classical singularity. The results show that the interaction energy obtained by classical elasticity is much greater (1.4 eV or so) than the experimental value. However the value obtained by non‐local elasticity is in very good agreement with the experimental value (0.5 eV). It is also proved that the nonlocal interaction energy is lower when in body‐centred cubiciron an interstitial carbon atom locates in the octahedral positions than in the tetrahedral posi

ISSN:0370-1972    

DOI:10.1002/pssb.2221630105

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractVarious decomposed AlZn alloys are investigated by positron lifetime and angular correlation technique in order to study the potential of positron method in estimating the composition of Guinier‐Preston zones. From experiments the curve shape parameters,S, the core annihilation rate, λc, and the number of free conduction electrons,z, derived from the zeros of the one‐dimensional Fourier‐transform of the angular correlation curve are estimated. The response of the various annihilation parameters to zone composition, positron affinity, and alloying effects (lattice change, charge transfer) is discussed. The number of free electrons per atom reflects most clearly the chemical composition of the

ISSN:0370-1972    

DOI:10.1002/pssb.2221630106

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractA procedure is presented to estimate from available thermodynamic data the leading order anharmonic coefficients, their volume derivatives, and the quasi‐harmonic terms in the framework of perturbation theory of lattice dynamics to the fourth order in the Hamiltonian. It consists of fitting the theoretical expressions of three functions of compressibility, heat capacity, and thermal expansion to experiment particularly tailored to minimize the effect of experimental errors. The capability of the procedure to produce stable and accurate results is tested through an application to NaCl. NaCl is chosen because of the large number of available independent data, which allows to study in detail the effect of external as well as internal errors. Accurate estimates are found to be possible. Referred to the 300 K volume and on the basis of all available data, the resulting leading order anharmonic parameters of NaCl areA2=(4.6 ± 0.6) x 10−4J mol−1K−2, dA2/d InV=(9 ± 4) x 10−4J mol−1K−2, while the quasiharmonic parameters are 〈ω 2i〉=(6.8 ± 0.2) × 1026s−2, 〈γi〉=1.57 ± 0.0

ISSN:0370-1972    

DOI:10.1002/pssb.2221630107

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY

摘要:

AbstractLow temperature specific heats of AgSb alloys of concentrations 0.89; 2.67; 3.7, and 4.72 at% are measured between 0.4 and 4.2 K. Experimental results for pure Ag and AgSb alloys obey the relationC=γT+ βT3with an experimental error of 2%. It is observed that the electronic specific heat coefficient, γ, increases linearly with the impurity concentration while the Debye temperature, θD, decreases linearly with the concentration. It is established that the change of γ on alloying can be expressed as Δγ=1/3c(Z– 1) by modifying the free electron result. Variation of the Debye temperature, θD, is believed to result from the change of mechanical properties of Ag. By employing Lindeman's melting theory it is shown that (θD)alloy=(1 – 0.63c) (θD)Agwhich agrees satisfactorily with the experim

ISSN:0370-1972    

DOI:10.1002/pssb.2221630108

出版商:WILEY‐VCH Verlag    

年代:1991

数据来源: WILEY