[en] In the present paper data related with hole centers migration in ZrO₂-Y₂O₃ crystals at temperature exceeding of the auto-localized holes temperature are cited. Capture of holes by impurities and hole defects is observed. The suggestion that something analogy should be observing for auto-localized excitons also is made

[en] Adsorption and luminescent properties of nominally pure crystals ZrO_x-Y₂O₂ are studied. The examined crystal were synthesized at stabilizer Y₂O₃ different concentrations after action of diverse doses of γ-rays, neutron fluences, thermal processing on air and vacuum. It is shown, that the key defect of ZrO_x-Y₂O₂ structure under Y₂O₃ concentration changing is oxygen vacancy, and F-center under γ-irradiation

[en] Full text: The thermo-luminescence or afterglow (AG) of quartz optical fibres (OF) of FVP-300 marks with contents of 1000 ppm OH groups and FIL with 10 ppm OH-group was studied after gamma γ-irradiations at 77 K to different doses in the temperature interval of 77-300 K. In the both OF types the AG was detected at 77K with the intensity decreasing while keeping at 77K and completely disappeared in 2-3 hours. The AG curves of both types FL contain peaks with maxima at 90, 95, 110, 130, 170 and 220 K. Besides, in FL with low contents OH-groups there is also a broad band at 260K. The intensities of peaks at 170, 220 and 260 K in OF with low contents of OH-groups are much higher than those for a large OH group contents. It means that higher contents of OH group suppresses the formation of these AG peaks. The comparative analysis of AG peaks of these OF types with literary data has shown their full coincidence with the data of work [1] on study of thermal luminescence of quartz crystal activated simultaneously by germanium and aluminum. We explained the studied radiation-stimulated changes in both OF types by analogy with the case of crystalline quartz with Ge and Al admixtures by Mackey model though it does not reflect completely all the processes of creation and annealing the centres. The essence of Mackey model is the following: during γ-irradiation of silicon dioxide at 77K [GeO₄]^- +[Al_e+O₄]+M⁺ centers are formed. Either heating up to 300K or long ageing at 77K (as in our case of OF) leads to the formation of [GeO₄]^-M⁺ +[Al_e+O₄]+hν type centres. References: 1. Tcinober L.I. Proceedings of the conference of All-union Scientific Research Institution of piezo-optic mineral crude, M., 1960, vol. 3, No 2, p. 95. (authors)

[en] Full text: Short-living and stationary color centers are studied in optic fibers (OF) with concentration of OH 1000 ppm at the temperatures of 77-300 K. As it was demonstrated in [1] concentration of OH of 1000 ppm in the optic fibers at room temperature does not observed. The studies showed that under irradiation at 77 K the color centers are formed with the absorption bands at 215, 260, 330 and 550 nm. In this work the idea was proposed that under irradiation with 105 Rad non-bridge oxygen atoms is not formed. This is supported by the researches showing that the band 215 nm, which is formed by E - centers, disappears at two values of temperature. The first E - centers disappear at 77 K, whereas the second one at 310 K. Here, the first E - center can be observed at 470-500 nm. Based on the stated above we assume that the values of OH concentration at 1000 ppm in optic fibers are not correct. It is obtained that at low temperatures of 77 - 300 K new phenomena are observed, i.e. existence of two E - color with peaks at 215 nm. The values of temperature at which these centers exist are different, the first exist at temperature up to 85 K, and the second one up to 300 K. (author) Reference: 1. V.B. Gavrilov, A.I. Golutvan, Yu.S. Gershtein et al. Absorption spectra in pure quartz optic fibers gamma-irradiated with 60Co source. // Instrumentation and techniques of experiment.- 1997.- No 4.- p. 23-32.

[en] Aims of inquiry: Study of the nature of the grown and radiation-induced structure defects of the proper electronic excitation and processes of their relaxation in the crystals of ZrO₂-Y₂O₃. Method of inquiry: Thermal flashing, optical absorption, photo-, gamma-, and thermal luminescence, stationary and pulse excitation. The results achieved and their novelty: Using a set of experimental research methods it was established: a dependence of vacancy concentration on Y₂O₃ concentration; nature of defect centers depending on type and concentration of activators; a role of electronic excitations on charge and energy transport. It was shown for the first time that the phosphorescence band at 480 nm is due to phosphorescence of self-trapped excitons. Based on the results obtained a novel view for the radiation-optical properties of complex solution type crystals ZrO₂-Y₂O₃ was worked out. (author)

No abstract available

[en] The cathodoluminescent (CL), γ-ray luminescence (GL) and thermostimulated luminescence (TSL) of ZrO₂-Y₂O₃ (10wt.%) (YSZ) crystals were investigated. Pulses of electrons with 300 eV energy, 10 ns duration and 100 A/cm² current density realized the CL excitation. The CL spectrum, being measured at 297 K at once after electron pulse excitation consists of two wide bands on 4.4 and 2.8 eV. The former is characterized by short decay time of about 60 ns. The attempt to defect this emission in TSL of γ-irradiated samples in the temperature range from 77 to 400 K wasn't crowned with success. These results allow to concluding that emission on 4.4 eV isn't connected with recombination of separated charge carries and due to exciton-like state, formed as a result of reciprocal attraction of electrons and holes in the course of relaxation. In 200 ns after pulse excitation only emission band on 2.8 eV appears, which is complex and consists of some bands with different decay times from hundred nanoseconds to a few ms. In a course of spectra relaxation two independent overlapping structures on 2.8 eV and 2.4 eV were observed such emission bands were defected in steady GL and TSL spectra. The short-wave emission band can be photoexcited in the fundamental absorption region on 4.2 eV at 77 K. That circumstance as well as large half width, essential stokes' shift allow to consider that this luminescence is intrinsic and can used by radiative decay of electron-hole-like excitations, resulting from recombination of electrons with (self) trapped holes ground state of which is deep settled in the gap band

[en] The termolighting, thermo-, photo- and γ-luminescence spectra of the ZrO₂-Y₂O₃ (88 mol. % ZrO₂) system crystals are studied. It is shown that two bands with the maxima 480 and 530 nm are observed within the temperature range 77-300 K. The comparative studies made it possible to relate the luminescence band 480 nm to the exciton-like state luminescence, originating by recombination of electron with holes autolocalized in the lattice regular nodes

[en] The cathodoluminescence (CL), X-ray luminescence (GL) and thermostimulated luminescence (TSL) of yttrium stabilized zirconia (YSZ) crystal were investigated. The experiments were performed on single crystals of ZrO₂-Y₂O₃ (10 wt. %). The GL excitation was realized by pulse of electrons with 300 eV energy and of 10 ns duration. The CL spectrum being measured at 297 K at once after electron pulse excitation consists of two wide bands on 4.4 and 2.8 eV. The former first was found in YSZ crystals and it is characterized by short-decay time of order of 60 ns at 297 K. This emission was not seen at 77 K because of intensive resorption short-wave region. The attempt to find this emission in TSL spectra γ-irradiated crystals was not successful. This result allow to conclude that emission at 4.4 eV is not connected with recombination of separated charge carriers and due to exciton-like state, formed as result reciprocal attraction of electrons and holes in the course of relaxation. In 100 ns after pulse excitation only emission band on 2,8 eV appears, which is complex and consists of some bands with different decay times from hundred ns to a few μs. In a course of spectrum relaxation two independent overlapping structures on 2.8 eV and 2.4 eV were observed such emission bands were defected in stationary GL and TSL spectra. The short-wave emission band can be photoexcited in fundamental absorption region on 2.2 eV at 77 K. That circumstance as well as half width, essential stokes' shift allow to consider this luminescence intrinsic and can used by radiative decay of electron-hole-like excitations, resulting from recombination of electrons with (sets) trapped holes cased state of which is deep settled in gap band. (author)

[en] This work intends to review some results on radiative recombination investigations. The γ and thermostimulated luminescence in Zr)_2-Y₂O₃ (12%) were studied. A characteristic green luminescence under γ-ray excitation was observed. The two thermo-luminescence bands of 2,6 and 2,3 eV were excited at 190 and 290 K respectively. When the short-wave luminescence band quenches, one can see the bleaching of typical low-temperature broad absorption band at the 2,2 eV. High temperature treatment in air leads to increasing of the intensity of the 2,6 eV band and decreasing of the 2,3 eV one. (A.A.D.)