2. Articole

Permanent URI for this collectionhttps://msuir.usm.md/handle/123456789/47

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Subject: search.filters.subject.Raman spectroscopy

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    Caracterizarea structurală a straturilor subțiri de Sb2Te3 fabricate prin metoda sublimării în volum cuazi-închis [Articol]
    (CEP USM, 2024) Untila, Dumitru; Lungu, Ion; Suman, Victor; Gadiac, Ivan; Potlog, Tamara
    Straturi subțiri de Sb2Te3 au fost obținute pe suporturi de sticlă ITO/CdS prin metoda sublimării în volum cuazi-închis (CSS). Prin analiza difracției razelor X, s-a constatat că straturile subțiri de Sb2Te3 au rețea cristalină hexagonală, ce aparține grupului spațial P6/mmm. Creșterea temperaturii evaporatorului de la 470°C până la 530°C, duce la modificarea orientării preferabile de creștere a cristalitelor compusului Sb2Te3 și la creșterea gradului de cristalinitate a acestuia. Investigațiile Raman, au confirmat rezultatele XRD și au fost folosite pentru a obține informații suplimentare asupra structurii straturilor subțiri de Sb2Te3. Caracteristica dubletului observat la 119,54 cm–1 și 138,83 cm–1, precum și la 93,65 cm-1 si 107,36 cm-1 cu intensitate integrală foarte mică pot fi atribuite interacțiunii Te-Te între pachetele de telurură de antimoniu.
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    Preparation and characterization of Ga2O3 and GaN nanoparticles [Articol]
    (SPIE, 2015) Rusu, Emil; Ursachi, Veaceslav; Raevschi, Simion; Vlazan, Paulina
    In this communication, we present results on preparation of GaN nanoparticles by conversion of Ga 2O 3 nanocrystals in a flow of NH 3 and H 2. The monoclinic Ga2O 3 nanoparticles have been prepared by hydrothermal method with gallium nitrate and sodium hydroxide as precursors. Ga2O 3 nanowires are produced with increasing the duration of the hydrothermal process up to 24 hours. The production of β-phase Ga2O 3 has been confirmed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. According to XRD, Raman and FTIR spectra, wurtzite type GaN nanocrystals with an average size of 28.6 nm are obtained by nitridation of Ga2O3 nanoparticles. Doping of Ga2O 3 nanomaterial with Eu 3+ ions in the hydrothermal process is demonstrated, and the emission spectra of this Eu-doped nanomaterial are compared with those of Eu-doped nanoparticles prepared previously by solid state reactions.
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    Oxygen-dependent formation of VO2 thin films by metalorganic aerosol deposition [Articol]
    (Universitatea Tehnică din Moldova, 2018-05-24) Belenchuk, Alexandr; Shapoval, Oleg M.; Zasavitsky, E.; Vatavu, Sergiu; Kiritsa, Arcady; Moshnyaga, V.
    We report on the growth and properties of vanadium dioxide (VO2) on amorphous and oriented substrates by the low-cost and industry-oriented method of metalorganic aerosol deposition (MAD). X-ray diffraction and temperature- dependent Raman spectroscopy confirm formation of single phase tin films. Abrupt change of resistance by 5×103 times and steep drop of infrared transmission from 49 to 10% at 1700 nm pave the way for application of MAD technique in fabrication of VO2-based optoelectronic and thermochromic devices, such as “smart windows”.