DEFECTS AND STRUCTURE OF DOPPED OXIDE CRYSTALS

N.Kulagin

Kharkov State University, av.Shakespeare 6-48, 310045 Kharkov, Ukraine. e-mail: kulagin@spin.univer.kharkov.ua

Pure and doped oxide crystals commom formula: A₂O₃, ABO₃ , A₂B₂C₃O₁₂ were investigated by different physical methods such as: X-Ray diffraction, Valency Shift of X-Ray Lines [1], ESR, optical spectroscopy , dielectric constant and non-linear properties.

The most interest results were obtained for pure and dopped Ti_xO_y, SrTiO₃, SrTiO₃: Me⁺³ and SrTiO₃: RE⁺³ samples [4]. Relation Sr/Ti ions (Ti/O also) and crystals density change more than 12 % from etalon sample under full stability of crystals lattice.

Non-optical properties such as bire-frequances and dichroism were studied for wide values of temperature. Interest properties of these crystals: high conductivity and blue cathodo-luminescence and anomalous of the phase transition under 105 K were observed.

Models of electronic structure of the doped crystals and schemes of physical processes are proposed here [7].

1. N. Kulagin, Sov Phys.Sol.Stat. 23 (1983) 3392-3397
2. N.Kulagin , D.Sviridov. Introduction to Doped Crystals Physics. Kharkov, 1990.
3. N.Kulagin, G.Trojan . Sov.Opt.Spectr. 77 (1993) 174-178
4. N.Kulagin, M.Ozerov. Sov.Phys.Sol.Stat. 35 (1993) 2472-2478
5. L.Korostel, N.Kulagin . Sov.Crystallography. 39 (1993) 1095-1099
6. N.Kulagin, L.Korostel. Izav RAN, ser fiz. 57 (1993) 2020-2025
7. N.A.Kulagin, D.T.Sviridov Methods of Electronic Structure Calculation for Free and Impurity Ions. Moscow. 1986