Publications by authors named "Andrey Tumarkin"

Article Synopsis
  • Strontium-barium niobate (SrBaNbO) films are promising for microwave applications due to their high dielectric nonlinearity and low losses.
  • The films were synthesized on sapphire substrates using magnetron sputtering, and their structural features were analyzed through various methods, focusing on Brillouin light scattering.
  • Brillouin light scattering proved to be an effective nondestructive technique for examining the films' structures, allowing precise determination of their thickness and unique properties influenced by acoustic wave scattering.
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Eu doped porous nanostructured SrTiO films and powder fabricated by sol-gel route without using any precursor template are characterized by different morphology and phase composition. The films show red and yellow luminescence with the most intensive photoluminescence (PL) bands at 612 nm and 588 nm, respectively. Raman, secondary ion mass spectrometry (SIMS), and X-ray diffraction (XRD) analysis of undoped nanostructured porous SrTiO films showed the presence of TiO, SrO, and SrTiO phases and their components.

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Based on porous silicate glasses obtained by ion exchange, glass-ceramic materials containing a solid solution of barium-strontium titanate with a dielectric constant of more than 100 at microwaves, were synthesized for the first time. Glass-ceramic structures were studied using X-ray diffraction, secondary electron microscopy, Mössbauer spectroscopy and porometry methods. Electrical characteristics such as permittivity and losses of as-prepared and annealed in oxygen medium samples were also investigated at microwaves.

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Experimental studies were conducted on the effects of lead oxide on the microstructure and the ferroelectric properties of lead zirconate-titanate (PZT) films obtained by the method of radio frequency (RF) magnetron sputtering of a ceramic PZT target and PbO powder with subsequent heat treatment. It is shown that the change in ferroelectric properties of polycrystalline PZT films is attributable to their heterophase structure with impurities of lead oxide. It is also shown that, even in the original stoichiometric PZT film, under certain conditions (temperature above 580 °C, duration greater than 70 min), impurities of lead oxide may be formed.

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The high dielectric constant ferroelectric-polymer nanocomposite was developed for producing the heat-resistant and chemical stable planar layers. According to the composite coatings formation conditions, the following value ranges of dielectric constant and loss factor were received: 30⁻400 for dielectric constant and 0.04⁻0.

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