Facultatea de Fizică
Universitatea "Al.I.Cuza" Iaşi
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| Titlu: Efectele galvanomagnetice în cristalele PbTe:Yb |
| Autori: Lucian Lungu |
| Afiliere: Societatea Ştiinţifică CYGNUS, Suceava |
| Abstract: AIVBIV compounds are widely used in IR technique. However, a number of technological problems are not solved up till now. Electrophysical properties of these compounds in many respects are determined by intrinsic defects of their crystal structure [1]. A significant pat of the latter is caused by deviation of the crystal composition from the stoichiometric one. The problem of a purposeful control of such properties, on the one hand, comes to a possibility to control intrinsic defects and stoichiometry of crystals. For this purpose, as a rule, a long-term (several weeks) isothermal annealing in atmosphere enriched with vapor of one of the components is used. Nevertheless, this method does not give a possibility to obtain crystals with the change carrier concentration less than 1016 cm-3 and with high homogeneity.
On the other hand, a purposeful doping with corresponding impurities can perform control of electrophysical parameters. It was found that the impurities of the III group (In, Ga) lead to appearance of a number of new effects noncharacteristic of undoped materials, such as the Fermi level stabilization, restrained photoconductivity and long term photomemory. |
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