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Information × Registration Number 0218U005479, 0117U006454 , R & D reports Title New effective polytypic acoustooptic materials based on cgalcogenide crystals of the TlInS2 group. Optimization of acoustooptic interaction geometry popup.stage_title Head Vasylkiv Yuriy Vasylyovych, Registration Date 04-12-2018 Organization Institute of Physical Optics named after O.G. Vlokh of Ministry of Education and Science of Ukraine popup.description2 Acoustic and elastic properties in the crystals of TlAB2 (A = In, Ga, B = S, Se, Te) family, namely in TlInSe2, TlGaSe2 crystals, have been investigated. The velocity of ultrasonic waves, which propagate in the main crystallographic planes in TlInSe2, TlGaSe2 crystals was determined by Papadakis method. In TlInSe2 crystals all components of the elastic stiffness and elastic pliability tensor are defined. The anisotropy of the acoustic waves velocity in TlInSe2 and TlGaSe2 crystals and the intersections of acoustic wave velocities are constructed. The device for investigating the photoconductive effect in the crystals of the family TlAB2 (A = In, Ga, B = S, Se, Te) by the Dixon-Cohen method with the subsequent refinement of the signs of the photovoltaic coefficients by the polarizational optical method is developed. The temperature behavior of the linear thermal expansion of TlInSe2 crystals belonging to the family TlAB2 (A = In, Ga, B = S, Se, Te) is studied. For all TlInSe2 crystals all nonzero components of the thermal expansion tensor are defined. On the basis of spectroelipsometric studies, the real and imaginary parts of the dielectric function of the TlInS2 crystal in the energy range 1-5 eV were determined in the temperature range of 130-293 K. It was found that in the phase transition region there are changes in the temperature behavior of all calculated parameters: the amplitudes, the energies of the critical points, the extension parameters and phases. Product Description popup.authors Бойко Віталій Теодорович Васильків Юрій Васильович Гомоннай Олександр Олександрович Запека Богдан Євгенович Кривий Тарас Тарасович Мись Оксана Григорівна popup.nrat_date 2020-04-02 Close