Browsing by Author "Lebedeva, N. N."

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Peculiarities of The Dielectric Response of The Silver-Modified-Zeolite Porous Microstructure
    (2016) Bunyatova, U.; Koc, S. Ozturk; Orbukh, V. I.; Eyvazova, G. M.; Agamaliev, Z. A.; Lebedeva, N. N.; Kocum, I. C.; Salamov, B. G.; Ozer, M.; J-5194-2019
    The aim of this study was to characterize electrical conductivity and dielectrical properties of the silver-exchanged zeolite-natural clinoptilolite from Western part of Turkey and Azerbaijan in the range of frequencies from 200 Hz to 1 MHz and at room temperature. For a better understanding the effect of concentration and content of silver in the nanoporous zeolite volume on the conductivity, a study of the dielectric properties of an un-modified and silver-modified zeolite plates with different amounts of Ag ions and Ag nanoparticles is performed. Un-modified and three different types of the silver ion-exchanged modified clinoptilolite plates were prepared. It was found, that with increasing silver concentration, resistance of zeolite plate monotonically decreases at the same time a capacitance is increases. It is suggested an explanation of the observed frequency dependence of the capacitance and resistance of zeolite plates on the silver concentrations may be explain on the basis of an electrode-dielectric interface gap model. At the same time, the observed phenomenon can be explained by considering the fact that with increasing content of silver the conductivity increases. These results show that Ag nanoparticles play significant role for performance improvement in plasma electronic devices with zeolite cathode. (C) 2016 Elsevier Ltd. All rights reserved.
  • No Thumbnail Available
    Item
    Peculiarities of Unusual Electret State in Porous Zeolite Microstructure
    (2017) Bunyatova, U.; Orbukh, V. I.; Eyvazova, G. M.; Lebedeva, N. N.; Agamaliev, Z. A.; Kocum, Lc.; Ozer, M.; Salamov, B. G.; J-5194-2019
    This study explores, for the first time to our knowledge, the influence of electret state on the dielectric parameters of porous zeolite of frequencies up to 106 Hz, at room temperature and normal atmospheric pressure. The I-V characteristics with unusual hysteresis loop in the wide pressure range were measured on zeolite plates having three different material characteristics: A) plate, cut out from a monoblock natural zeolite; B) plate, modified by silver ions, and C) plate containing silver nanoparticles. Zeolite samples were exposed to an electric field (E-p = 2 kV cm(-1)) in an air atmosphere for 240 min. It is established, that the stability of electret state and value of the dielectric response epsilon' and epsilon" for clinoptilolite Ag nanoparticles containing plates changed under influence of DC electric field. During some time the dielectric response is restored and observed unique phenomenon indicates on the electret behavior of clinoptilolite samples. These changes are observed within a few days consequently, there is long-term dynamics of the dielectric response changes. This interpretation is based on the assumption that due influence of the dc electric field part of the silver atoms in nanoparticles decays into ions and electrons. (C) 2017 Elsevier Ltd. All rights reserved.