Nanocomposites and nanomaterials

Tellurite glass with alkali metal oxides and its acousto-optic efficiency
Agarkov K.V., Sadovskaya L.Ya.
Oles Honchar Dnipro National University, Gagarin Avenue, 72, Dnipro, 49010, Ukraine. 
E-mail: electrophysicsdnu@gmail.com

This report presents the results of a study of certain properties of glass, the main composition of which is paratellurite (TeO2 is more than 95 %). Paratellurite is vitrified in the presence of other oxides [1]. There are the number of known vitrescent additives, such as oxides of germanium, silicon, phosphorus and others. It is possible to obtain a bulk glass with an extremely high content of paratellurite by using alkali metal oxides. A synthesis technology has been developed that allows obtaining ingots limited only by the dimensions of the container. The production of glass is confirmed by X-measurements.
Obtained tellurite glass has a yellowish color, is transparent in the wavelength range from 0.4 μm to 6.55 μm. The optical transmission is about 83 %. The refractive index varies from 2.02 (λ = 0.7065 μm) to 2.1351 (λ = 0.4046 μm). At room temperature and at a frequency of 1 kHz, the dielectric constant is 31 and the conductivity on alternating current is of the order of 9 • 10 -11 Ω -1 • cm -1.
The acousto-optic parameters were measured at room temperature by the Dixon-Cohen method by comparison with a quartz standard. The acoustic attenuation was determined from the magnitude of the signal at different points of the sample. All parameters were obtained at a wavelength of 0.633 μm. The propagation velocities values of an acoustic wave were determined by the Schaeffer-Bergman method.
The velocity of the longitudinal and transverse acoustic waves is 3.35 km/s and 1.97 km/s, respectively, the acousto-optic efficiency of M2 = 20 • 10 -18 s 3/g and the attenuation of sound is 2.1 dB/cm at a frequency of 90 MHz.
А number of advantages of obtained material, such as optical homogeneity, a relatively small attenuation of sound, seem promising for acoustooptic instrumentation. This glass is a good container for nanoparticles of semiconductors and metals.

1.	Rivera V.A.G., Manzani Danilo. (Editors). Technological advances in tellurite glasses. Properties, processing and applications. // Springer.-2017. -334 p.