Browsing by Author "Zalamai, Victor"

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    ELABORAREA ȘI STUDIUL AEROMATERIALULUI ÎN BAZĂ DE TiO2 PENTRU APLICAȚII FOTOCATALITICE
    (CEP USM, 2024) Busuioc, Simon; Ciobanu, Vladimir; Braniște, Tudor; Zalamai, Victor; Ursachi, Veaceslav; Monaico, Eduard; Tighineanu, Ion
    We report on the fabrication process of TiO2 -based aeromaterial for environmental applica tions, such as wastewater treatment or as activated photocatalytic air filters. The TiO2 aeromate rial is obtained by Atomic Layer Deposition technique with the thickness of 50 nm on a substrate template consisting of ZnO microtetrapods, followed by the selective chemical etching of the ZnO template. The morphological and optical properties, chemical composition and crystalline quality of the fabricated aeromaterial are investigated. By implementing specific technological steps to enhance the crystalline quality of the TiO2 aeromaterial, it was possible to obtain materi als with either anatase phases or a mixed anatase-rutile phase.
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    Studies of vanadium and vanadium oxide based nanocomposite structures [Articol]
    (2017) Prilepov, Vladimir; Gashin, Peter A.; Popescu, Mihai; Zalamai, Victor; Spoiala, Dorin; Ketrush, Petru; Nasedchina, Nadejda
    The results of the surface morphology studies as well as optical and electrical properties of nano-dimensional vanadium oxide composite structures deposited on various substrates- silica, glass substrates covered by conducting layer of SnO2, pure pyroceramics plates and the same covered by Al2O3, SiO2, Ta2O5 layers are presented. According to Raman spectroscopy results the thin film structure obtained on quartz corresponds to the -V2O5 orthorhombic phase. In contrast with this the Raman spectra of V2O5 films obtained on pyroceramics substrates, passivated by Al2O3, Ta2O5, SiO2 oxides, do not appear clearly marked narrow lines which indicate their amorphous character. The investigation of the optical properties of the fabricated layers in the spectral range of 200-1000 nm had revealed the presence of both allowed direct and indirect electron transitions. In the frequency range of 103-107 Hz the real Z' and imaginary Z'' part of the total impedance of pyroceramics/Al2O3/Al/V2O5/Al structure were studied. The applied direct bias leads to a considerable Z', as well as Z'' decrease. The analysis of the obtained dependencies is carried out by using the method of equivalent circuits.