MUTUAL TRANSFORMATION OF ELECTRONIC CENTERS IN IMPURITY ALKALI-HALOID CRYSTALS

DOI:10.25140/2411-5363-2017-2(8)-135-142

Author:

Kovtun Anatolii, Chernihiv National University of Technology (95 Shevchenka Str., 14027 Chernihiv, Ukraine)

Dymerets Andriy, Chernihiv National University of Technology (95 Shevchenka Str., 14027 Chernihiv, Ukraine)

Language: russian

Annotation:

Urgency of the research. Nowadays, information storage is a very important task. Thus, a new way of recording large amounts of informationwhen using the minimum storage size will be relevant.

Target setting. Investigate the possibility of recording information in KCl + LiCl crystals, as well as a mechanism that allows doing this.

Actual scientific researches and issues analysis. In the work of N.N. Baran. et al. "Dual electron-nuclear resonance of A-centers in mixed crystals of KCl + LiCl" by the

DENR method confirmed the model of the FA-center, but the kinetics of the interconversion of  has not been studied sufficiently.

Uninvestigated parts of general matters defining. Theoretically, the mechanism of recording information when converting electronic centers by using the tunnel effect is understandable, but in reality it has not yet been realized.

The research objective. Experimentally and theoretically investigate the kinetics of mutual conversion of electron centers FFA in KCl crystals with an admixture of Li+ ions. In the process of research, it is necessary to show the mechanism of transformation

F centers to FA-centers, as well as its practical use for recording information.

The statement of basic materials. Experimental and theoretical research of the phototransformation kinetics of FFA in KCl + 1 mol% LiCl crystals in a charge are carried out. It is shown that the mechanism of transformation of F-centers to FA-centers consist in the fact that when the crystals are lighted, the F-centers go over into an excited state and give electrons to the conduction band as a result of electron-phonon interaction. During the lifetime of electrons in the conduction band, free haloid vacancies are stabilized by impurity ions because of diffusion. Then, the stabilized haloid vacancies are transformed to FA-centers by attaching electrons. It is shown that the filling of nearby haloid vacancies by tunneling of electrons of excited F-centers in the X-rays irradiated (γ-rays) crystals occurs only partially. It is proposed to use the tunnel effect to record information with a focused beam from a quantum light generator. The recorded information can be erased by a defocused light beam.

Conclusions. Proposed mechanism to convert the F-centers in FA-centers in ionic crystals KCl mixed with cations Li+, and the kinetics of this transformation. This mechanism is proposed to be used for recording information.

Key words:

FA-centers, haloid vacancies, quantum yield, tunnel effect, foreign alkaline ions, conduction band, phototransformation of centers

References:

1. Baran N. N. (1968). Dvoinoi elektronno-iadernyi rezonans A-tsentrov v smeshannykh kristallakh KCl+LiCl [Dual electron-nuclear resonance of A-centers in mixed crystals of KCl + LiCl]. Fizika tverdogo tela – Solid State Physics, vol. 10, pp. 3005–3010 (in Russian).

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8. Gorbenko, P.K., Kovtun, A.A., Rogoza, A.V., Sholomii, Iu. E. (2014). Issledovanie radiatsionnykh defektov v kristallakh KCl chistykh i s primesiu ionov Li+ и Na+ [Investigation of radiation defects in KCl crystals of pure and Li+ и Na+]. Visnyk Chernihivskoho derzhavnoho tekhnolohichnoho universytetu. Seriia “Tekhnichni nauky” – Visnyk of Chernihiv State Technological University. Series “Technical sciences”, no. 2 (73), pp. 2933 (in Russian).

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