摘要:

X-ray diffraction, electrical conductivity and IR studies been carried out for the various compositions of the ternary system AgI-Ag2SO4-AgPO3. Based on the results, a tentative structure has been indicated.

ISSN:1042-0150    

DOI:10.1080/10420159108224864

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

7Li nuclear spin relaxation and electrical conductivity measurements were performed as a function of temperature for varying Li content in (1-x)GeO2:xLi2O glass series where x=0. 01 to 0. 36. Above room temperature the nuclear spin relaxation rate increases exponentially with rising temperature giving an activation energy ENMRwhich is always lower than the activation energy Eδfor dc conductivity. However, below x=0. 1 ENMRincreases rapidly with decreasing x and is found to approach Eδfor x approaching zero. The result is discussed in view of a motion of the Li ions correlated by Coulomb interaction.

ISSN:1042-0150    

DOI:10.1080/10420159108224865

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Onset of electric current has been detected on illuminating the near–contact regions of RbAg4I5crystals. The spectral and temperature characteristics of this current have been studied. A method is proposed for studying the spectrum of electronic states in the α-phase of the RbAg4I5crystal. The dependence of the magnitude of the current and its spectral characteristics on the particular region of the RbAg4I5crystal which is exposed to the light was used for the analysis of the variations in the distribution of defects along the length of the sample and the processes which occur near the electrode-(solid electrolyte) junctions.

ISSN:1042-0150    

DOI:10.1080/10420159108224866

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

We discuss the derivation of the formation enthalpy and entropy of the individual native defect components of AgBr, AgCl, and NaCl, from measurements of the subsurface ionic space charge potential. The straighforward intrinsic analysis for AgBr yields a silver vacancy formation energy of (0.30±0.04)eV + (7.2 ± 2.0)kT. The NaCl analysis involves some assumptions about impurity concentrations and association, and yields a cation vacancy formation free energy of (1.24 ± 0.12) − (6.53 ± 1.4) kT. For NaCl, the formation energy is divided almost equally between the two vacancies; in AgBr and AgCl the silver interstitial formation free energy vanishes when extrapolated to the melting point.

ISSN:1042-0150    

DOI:10.1080/10420159108224867

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

This study reports investigations into the characterization of intrinsic and extrinsic defect sites in SnO2. The techniques employed in these investigations include the use of EXAFS in conjunction with static lattice computer simulations of pure SnO2and SnO2doped with the aliovalent cations Sb and Ga.

ISSN:1042-0150    

DOI:10.1080/10420159108224868

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:1042-0150    

DOI:10.1080/10420159108224869

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Rutile, TiO2having relatively high melting point exhibits strong optical absorption after neutron irradiation (8 × 1016nr/cm2) at 15K. The band peak is located near 0. 96 μ having FWHM 0. 87 eV (at LNT). After inverse recovery at 120K, lattice defects due probably to F centers are annealed out at about 220K.

ISSN:1042-0150    

DOI:10.1080/10420159108224870

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

ITC measurements, optical absorption spectra in the wavenumber range 5.4 × 104−200 cm−1, microspectrophotometry, photoluminescence spectra, optical and electron microscopy and X-ray diffraction have been used to study the growth and the nature of a new phase occlusions in LiF: Ti3+and LiF: Mg2+, Ti3+. They grow along the 100 direction as a consequence of high temperature heat treatments in moist atmosphere.

ISSN:1042-0150    

DOI:10.1080/10420159108224871

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

By monitoring the magnetic circular dichroism (MCD) of F-centers in irradiated alkali halides EPR of impurity centers was detected without microwaves due to a cross-relaxation of the impurities with optically pumped F-centers. Cross-relaxation effects were also observed in magnetic resonance detected via MCD in absorption and the intensity of spin-dependent recombination emission in ionic crystals doped with transition and rare earth ions.

ISSN:1042-0150    

DOI:10.1080/10420159108224872

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Using both the Self-Consistent Charge Extended Hücel and MS-Xα methods the theoretical dependence of the [g]-tensor of NiF63-complexes on the equatorial (Req) and axial (Rax) Ni+-F−distances has been calculated and its microscopic origin discussed. The present results explain reasonably well the experimental values corresponding to the Ni+centres, termed as I, II, III in fluoroperovskites, pointing out that the presence of the two axial vacancies in centre III is well reflected in the (g-g0) factor. The present study reveals that the δReqchanges (induced by hydrostatic on chemical pressures) down to .2 pm can be detected from the corresponding zvariations.

ISSN:1042-0150    

DOI:10.1080/10420159108224873

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor