摘要:

We have undertaken a fundamental study of heterodiffusion of foreign ions in pure single crystals. The present work describes the measurements of the diffusion coefficient of monovalent cations in some alkali halides, namely Na+and Rb+into KCl, KBr, NaI and KI. The priority is given to the super-accuracy of the experimental data. The target is to test the validity of the existing theories for calculating the enthalpy and entropy of migration.

ISSN:1042-0150    

DOI:10.1080/10420159108224854

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Two peaks at 355 and 525K appear in the thermoluminescence spectrum of polycrystalline spinel X-irradiated at room temperature. They are due to thermally released electrons which recombine at several impurity centres as well as at V-centres. The influence of defects arising from the structural disorder and the non-stoichiometry of samples is discussed.

ISSN:1042-0150    

DOI:10.1080/10420159108224855

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

In this paper the simple model for thermoluminescence is extended with the possibility of small changes in activation energy. These changes are interpreted as a consequence of trap-defect interactions and defect mobility. It is shown by simulation that the glow curve (TL-signal as a function of temperature) shifts to lower temperatures and its shape becomes more peaked by increasing the rate of change in activation energy.

ISSN:1042-0150    

DOI:10.1080/10420159108224856

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Thermoluminescence, absorption and luminescence spectra of as grown and well aged non-irradiated KCI(1-x)Brxcrystals, containing an average of 150 ppm of EuCl2as a dopant are analyzed as a function of the sample composition. The precipitation state of the KCl(1-x)Brxsystem is characterized by optical absorption and luminescence measurements.

ISSN:1042-0150    

DOI:10.1080/10420159108224857

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:1042-0150    

DOI:10.1080/10420159108224858

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

We have measured the X-ray induced emission spectra, the photoelectron yields/MeV gamma ray energy, and the scintillation decay times of BaF2doped with 0. 002 to 10 mol% Ce3+. The results will be compared with results obtained for pure BaF2and La3+doped BaF2crystals. A model for the scintillation mechanisms in these crystals will be proposed which explains qualitatively the influence of the type of doping and its concentration on the wavelength dependence and time dependence of the scintillation light output.

ISSN:1042-0150    

DOI:10.1080/10420159108224859

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The term “crossluminescence” (CRL) was originaly proposed for emission due to electronic transitions from valence band states to cation core band states. Analogous transitions involving cation core states are observed at defect centers.

ISSN:1042-0150    

DOI:10.1080/10420159108224860

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Thermostimulated electronic recombination processes have been studied by means of the fractional glow technique in KCl-T1, CaF2, LiF-Mg, Ti and Al2O3crystals in the temperature range where the ionic motion arises. A novel model concerning dynamic disordering for describing the kinetics of thermostimulated luminescence is developed, which takes into account the fluctuational changes of the trap spatial structure as well as its interaction with mobile ions and/or vacancies.

ISSN:1042-0150    

DOI:10.1080/10420159108224861

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The results of the tracer diffusion of Ag+by chemical microsectioning technique in AgBr/I sheet crystals up to the solubility limit in the temperature range 110–240°C are presented. The monotonic increase in the diffusivity and decrease of the activation enthalpy for diffusion with the increase of the iodide component in AgBr result from the decrease of the formation energy for Frenkel defects with the increase of elastic strain introduced by the oversized iodide ions.

ISSN:1042-0150    

DOI:10.1080/10420159108224862

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The results of a study of thermodynamic and electrical properties of Cd1-xPbxF2crystals are presented. A correlation between ionic conductivity and thermodynamic parameters in Cd1-xPbxF2crystals has been found.

ISSN:1042-0150    

DOI:10.1080/10420159108224863

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor