http://arthra.ugal.ro/handle/20.500.14043/25743 2026-04-18T12:04:58Z http://arthra.ugal.ro/handle/20.500.14043/25757 Fabrication and Characterization of Cobalt/Iron Composite Coatings Gheorghieș, Livia Cobalt/iron composite coatings are used in micro-equipments due to their high magnetic saturation values and Curie temperatures, as magnetic nanoparticles capable of killing cancer cells, for magnetic data storage and magnetic resonance imaging (MRI) and in coatings, plastics, nanowire, nanofiber and textiles as well as in certain alloys and in catalyst applications. Cobalt/iron composite coatings were prepared by using two types of solution consisting of oleic acid in diphenyl ether and cobalt formate strongly stirred then centrifuged and drayed. Obtained coatings were subjected to chemical and structural analysis by using EDAX and XRD techniques. Some magnetic characteristics have been estimated by drawing the hysteresis loop for various thicknesses of coatings. The Annals of "Dunarea de Jos" University of Galati Fascicle IX Metallurgy and Materials Science N0. 2 – 2013, ISSN 1453 – 083X 2013-01-01T00:00:00Z http://arthra.ugal.ro/handle/20.500.14043/25756 High-Dielectric Inorganic-Organic Hybrid thin Films for fie;ld Effect Transistors (FETFT) Vâlcu (Herbei), Elena Emanuela; Mușat, Viorica; Oertel, Susanne; Jank, Michael The paper discusses the challenges to develop thin films transistors for flexible transparent electronics, displays etc. The sol-gel preparation of hybrid thin films based on dielectric oxides nanoparticles (SiO2 NPs, ZrO2 NPs) and polymethy methacrylate (PMMA) is presented. The high-k hybrid thin films, evaluated as gate dielectric in a MIM structures, were deposed by spin-coating teqhnique. The multilayers (thin films) configuration of MIM structures were investigated by scanning electron microscopy (SEM) and electrical properties. The I-V and C-V curves showed a better dielectric behavior of hybrid films with respect to the simple PMMA films. Dielectric constant values of 2.1, 3.4 and 5.4 have been obtained for PMMA, ZrO2-PMMA and SiO2-PMMA films, respectively. The Annals of "Dunarea de Jos" University of Galati Fascicle IX Metallurgy and Materials Science N0. 2 – 2013, ISSN 1453 – 083X 2013-01-01T00:00:00Z http://arthra.ugal.ro/handle/20.500.14043/25755 Emphasizing Physical Aspects and Applications of Graphenes Baștiurea, Marian; Rodeanu, Magdalena Silvia; Dima, Dumitru Graphenes have attracted much attention due to their properties and possible applications. This approach is dedicated to shortly describe the problems related to this promising element. Some aspects concerning physical description and material characteristics are discussed. The paper presents methods for graphenes obtaining and major means of morphological investigation and structural characterization. Also, mechanical, thermal and tribological properties are reviewed. Finally, concluding remarks are drown. The Annals of "Dunarea de Jos" University of Galati Fascicle IX Metallurgy and Materials Science N0. 2 – 2013, ISSN 1453 – 083X 2018-01-01T00:00:00Z http://arthra.ugal.ro/handle/20.500.14043/25754 Photocatalytic Properties of Semiconductive Oxide Nanoparticles. From Fundamentals to Applications Ibănescu (Bușilă), Mariana; Mușat, Viorica; Textor, Torsten; Mahltig, Boris Photocatalysis is a promising technology that demonstrated important applications in environmental systems such as air purification, pollution removal, self-cleaning and antimicrobial. Semiconductive oxides (e.g., ZnO, TiO2, CuO) are important photocatalytic materials that can act as sensitizes for light based redox processes due to their electronic structure, which is characterized by the conduction-band with electrons (good reductants) and the valence band with holes (powerful oxidants). Excitation of electrons from the conduction-band and valenceband holes can react with electron donors and electron acceptors adsorbed on the semiconductor surface and electric double layer around the particles. The band gap value determines the semiconductive behavior of oxide nanoparticles. The absorption of UV-Vis radiation is an important tool for evaluating photocatalytic behavior of the obtained semiconductive nanoparticles. In this paper we present the correlation between the band gap value, particle size and the photocatalytic activity of ZnO nanoparticles prepared via an aqueous solution chemical method. The Annals of "Dunarea de Jos" University of Galati Fascicle IX Metallurgy and Materials Science N0. 2 – 2013, ISSN 1453 – 083X 2013-01-01T00:00:00Z