ИСТИНА

Complex molybdate crystals have a wide application as cryogenic scintillators for recording double beta decay of the "dark matter", acousto-optic modulators of laser radiation, etc. [1]. In the presented research LiNa5Mo9O30 single crystal has been grown by the Czochralski technique with 10 K/cm temperature gradient from a stoichiometric composition to an oriented seed. The heat conditions of the growth setup were chosen using the numerical simulation. The grown crystal was subjected by X-ray sectional topography and UV/VIS spectroscopy. Luminescent properties were analyzed using selective excitation in the UV/VUV spectral range in the temperature range of 4.2-300 K, and also with excitation by an electron beam. It has been shown that the luminescence spectra consist of two spectrally overlapping broad bands with maxima at 600 and 650 nm. On the basis of temperature and luminescence bands intensity relationships the activation energies of the intracenter thermal quenching process was identified. The analysis of excitation spectra as well as kinetic characteristics of the luminescence bands made it possible to draw conclusions about the nature of luminescence centers responsible for the observed bands. A spectrum of ultrafast intraband luminescence was obtained through excitation by a high-energy electron beam, and an estimate of the light output of this type of luminescence was made. [1] T.B. Bekker, N. Coron, F.A. Danevich, et al., Astroparticle Physics, 2016, v.72, pp. 38-45.