ISSN:0370-1972    

DOI:10.1002/pssb.2221150149

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221150150

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractMagnetic and neutron diffraction investigations on polycrystalline samples of TmFe1−xMnxO3compounds (x= 0.1 andx= 0.3) reveal some interesting features of the Mn3+‐ion influence on the thulium orthoferrite magnetic properties. Preliminary X‐ray diffraction data indicate an increase of the unit cell distortion with growing content of Mn3+ions. A decrease of the Néel temperature with higher Mn3+amount is observed. For the compound withx= 0.1 a reorientation transition from GxFzto GzFx(Γ4− Γ2) spin configuration is observed, whereas in the case of the compound withx= 0.3 a phase transition to antiferromagnetic phase (Γ1) is established. The neutron diffraction results point out to the occurrence of a complicated transitions sequence in th

ISSN:0370-1972    

DOI:10.1002/pssb.2221150104

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221150151

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractA theoretical approach to the study of both, the energy of a hydrogen impurity in a metal and the metal‐hydrogen impurity interaction is described. The analysis involves the virial and Hellmann Feynman theorems and the Kohn‐Sham formalism. Detailed calculations are performed for the case of hydrogen in aluminium. It is found that the non‐spherical component of the hydrogen induced electronic structure greatly modifies the hydrogen‐aluminium interaction, and the aluminium lattice expands about both, octahedrally and tetrahedrally sited impurities. These results, and the determination of the electric field gradient, compare favourably with those obtained from muon spin rotation experiments on such

ISSN:0370-1972    

DOI:10.1002/pssb.2221150105

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221150152

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221150153

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractThe susceptibility and specific heat of spin glasses for an Ising model in the presence of a magnetic field are calculated. Gaussian probability distribution is taken for exchange interaction with positive meanJ0. It is shown that the presence ofJ0enhances the reduction of susceptibility and specific heat around the freezing temperature.

ISSN:0370-1972    

DOI:10.1002/pssb.2221150106

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractAn analysis is made of the dielectric behaviour and the anharmonic contribution to the dielectric constants of AgCl, AgBr, TlCl, TlBr, CaF2, SrF2, BaF2, and PbF2crystals. The volume and temperature derivatives of static and electronic dielectric constants, and of the energy gap between bonding and antibonding states are derived from the experimental data using Phillips‐Van Vechten dielectric theory. The temperature derivatives of dielectric constants at constant volumes are used to estimate the magnitudes of anharmonic contributions. The effect of anharmonicity is discussed in terms of different theories. The volume derivatives of static dielectric constant are calculated using the Born‐Meyer theory of interionic potentials. The calculated quantities are compared with available experimental data. The applicability of the Mott‐Littleton theory of dielectric polarization is also discussed for the crystals under

ISSN:0370-1972    

DOI:10.1002/pssb.2221150107

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY

摘要:

AbstractCO2‐laser produced damping of electron‐hole drop (EHD) luminescence in Ge at laser intensities of 104to 5 × 106W/cm2is reported. The observed effect is explained to be due to heating of the EHD by 10.6 μm radiation and driving of e‐h plasma by phonon wind generated during absorption and relaxation of hot nonequilibrium c

ISSN:0370-1972    

DOI:10.1002/pssb.2221150108

出版商:WILEY‐VCH Verlag    

年代:1983

数据来源: WILEY