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The current work aimed to characterize the morphology, chemical, and mechanical properties of Pt and PtTi thin films deposited via thermionic vacuum arc (TVA) method on glass and silicon substrates. The deposited thin films were characterized by means of a scanning electron microscope technique (SEM). The quantitative elemental microanalysis was done using energy-dispersive X-ray spectroscopy (EDS). The tribological properties were studied by a ball-on-disc tribometer, and the mechanical properties were measured using nanoindentation tests. The roughness, as well as the micro and nanoscale features, were characterized using atomic force microscopy (AFM) and transmission electron microscopy (TEM). The wettability of the deposited Pt and PtTi thin films was investigated by the surface free energy evaluation (SFE) method. The purpose of our study was to prove the potential applications of Pt-based thin films in fields, such as nanoelectronics, fuel cells, medicine, and materials science.
Sebastian Cozma; Rodica Vlǎdoiu; Aurelia Mandes; Virginia Dinca; Gabriel Prodan; Vilma Buršíková. Characterization of Platinum-Based Thin Films Deposited by Thermionic Vacuum Arc (TVA) Method. Materials 2020, 13, 1796 .
AMA StyleSebastian Cozma, Rodica Vlǎdoiu, Aurelia Mandes, Virginia Dinca, Gabriel Prodan, Vilma Buršíková. Characterization of Platinum-Based Thin Films Deposited by Thermionic Vacuum Arc (TVA) Method. Materials. 2020; 13 (7):1796.
Chicago/Turabian StyleSebastian Cozma; Rodica Vlǎdoiu; Aurelia Mandes; Virginia Dinca; Gabriel Prodan; Vilma Buršíková. 2020. "Characterization of Platinum-Based Thin Films Deposited by Thermionic Vacuum Arc (TVA) Method." Materials 13, no. 7: 1796.
We report on the fabrication of dye-sensitized solar cells with a TiO2 buffer layer between the transparent conductive oxide substrate and the mesoporous TiO2 film, in order to improve the photovoltaic conversion efficiency of the device. The buffer layer was fabricated by pulsed laser deposition whereas the mesoporous film by the doctor blade method, using TiO2 paste obtained by the sol-gel technique. The buffer layer was deposited in either oxygen (10 Pa and 50 Pa) or argon (10 Pa and 50 Pa) onto transparent conducting oxide glass kept at room temperature. The cross-section scanning electron microscopy image showed differences in layer morphology and thickness, depending on the deposition conditions. Transmission electron microscopy studies of the TiO2 buffer layers indicated that films consisted of grains with typical diameters of 10 nm to 30 nm. We found that the photovoltaic conversion efficiencies, determined under standard air mass 1.5 global (AM 1.5G) conditions, of the solar cells with a buffer layer are more than two times larger than those of the standard cells. The best performance was reached for buffer layers deposited at 10 Pa O2. We discuss the processes that take place in the device and emphasize the role of the brush-like buffer layer in the performance increase.
Jeanina Lungu; Gabriel Socol; George E. Stan; Nicolaie Ştefan; Cătălin Luculescu; Adrian Georgescu; Gianina Popescu-Pelin; Gabriel Prodan; Mihai A. Gîrţu; Ion N. Mihăilescu. Pulsed Laser Fabrication of TiO2 Buffer Layers for Dye Sensitized Solar Cells. Nanomaterials 2019, 9, 746 .
AMA StyleJeanina Lungu, Gabriel Socol, George E. Stan, Nicolaie Ştefan, Cătălin Luculescu, Adrian Georgescu, Gianina Popescu-Pelin, Gabriel Prodan, Mihai A. Gîrţu, Ion N. Mihăilescu. Pulsed Laser Fabrication of TiO2 Buffer Layers for Dye Sensitized Solar Cells. Nanomaterials. 2019; 9 (5):746.
Chicago/Turabian StyleJeanina Lungu; Gabriel Socol; George E. Stan; Nicolaie Ştefan; Cătălin Luculescu; Adrian Georgescu; Gianina Popescu-Pelin; Gabriel Prodan; Mihai A. Gîrţu; Ion N. Mihăilescu. 2019. "Pulsed Laser Fabrication of TiO2 Buffer Layers for Dye Sensitized Solar Cells." Nanomaterials 9, no. 5: 746.
Zn/F co-doped SnO2 nanoparticles with a mean diameter of less than 15 nm and a narrow size distribution were synthesized by a one-step laser pyrolysis technique using a reactive mixture containing tetramethyltin (SnMe4) and diethylzinc (ZnEt2) vapors, diluted Ar, O2 and SF6. Their structural, morphological, optical and electrical properties are reported in this work. The X-ray diffraction (XRD) analysis shows that the nanoparticles possess a tetragonal SnO2 crystalline structure. The main diffraction patterns of stannous fluoride (SnF2) were also identified and a reduction in intensity with increasing Zn percentage was evidenced. For the elemental composition estimation, energy dispersion X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) measurements were performed. In general, both analyses showed that the Zn percentage increases with increasing ZnEt2 flow, accompanied at the same time by a decrease in the amount of F in the nanopowders when the same SF6 flow was employed. The Raman spectra of the nanoparticles show the influence of both Zn and F content and crystallite size. The fluorine presence is due to the catalytic partial decomposition of the SF6 laser energy transfer agent. In direct correlation with the increase in the Zn doping level, the bandgap of co-doped nanoparticles shifts to lower energy (from 3.55 to 2.88 eV for the highest Zn dopant concentration).
Florian Dumitrache; Iuliana P. Morjan; Elena Dutu; Ion Morjan; Claudiu Teodor Fleaca; Monica Scarisoreanu; Alina Ilie; Marius Dumitru; Cristian Mihailescu; Adriana Smarandache; Gabriel Prodan. Zn/F-doped tin oxide nanoparticles synthesized by laser pyrolysis: structural and optical properties. Beilstein Journal of Nanotechnology 2019, 10, 9 -21.
AMA StyleFlorian Dumitrache, Iuliana P. Morjan, Elena Dutu, Ion Morjan, Claudiu Teodor Fleaca, Monica Scarisoreanu, Alina Ilie, Marius Dumitru, Cristian Mihailescu, Adriana Smarandache, Gabriel Prodan. Zn/F-doped tin oxide nanoparticles synthesized by laser pyrolysis: structural and optical properties. Beilstein Journal of Nanotechnology. 2019; 10 (1):9-21.
Chicago/Turabian StyleFlorian Dumitrache; Iuliana P. Morjan; Elena Dutu; Ion Morjan; Claudiu Teodor Fleaca; Monica Scarisoreanu; Alina Ilie; Marius Dumitru; Cristian Mihailescu; Adriana Smarandache; Gabriel Prodan. 2019. "Zn/F-doped tin oxide nanoparticles synthesized by laser pyrolysis: structural and optical properties." Beilstein Journal of Nanotechnology 10, no. 1: 9-21.
To synthesize Carbon-Titanium (C-Ti) multilayer thin films deposited on silicon substrates was used Thermionic Vacuum Arc (TVA) method. The coated layers consisted of a base layer of about 100 nm of Carbon deposited at low evaporation rates. Subsequently, seven Carbon and Titanium layers were deposited alternatively on top of Carbon base layer, each of them has a final thickness up to 40 nm. In this study we obtained different batches of samples by variation of the substrate temperature between 0°C and 300°C, and the ion acceleration voltage applying a negative substrate bias voltage between 0V and -700V. To characterize the microstructure properties of as prepared C-Ti multilayer structures were used Electron Microscopy techniques (TEM, SEM, STEM) and Raman Spectroscopy. Results of tribological measurements are associated with the occurrence of atomic diffusion processes at Ti/C interface. To characterize the electrical conductive properties, the electrical resistance versus temperature have been measured.
Victor Ciupină; Cristian P. Lungu; Eugeniu Vasile; Gabriel C. Prodan; Corneliu Porosnicu; Rodica Vladoiu; Aurelia Mandes; Virginia Dinca; Virginia Nicolescu; Madalina Prodan; Radu Manu. Carbon-titanium multilayer films: Synthesis and characterization. AIP Conference Proceedings 2018, 2042, 020034 .
AMA StyleVictor Ciupină, Cristian P. Lungu, Eugeniu Vasile, Gabriel C. Prodan, Corneliu Porosnicu, Rodica Vladoiu, Aurelia Mandes, Virginia Dinca, Virginia Nicolescu, Madalina Prodan, Radu Manu. Carbon-titanium multilayer films: Synthesis and characterization. AIP Conference Proceedings. 2018; 2042 (1):020034.
Chicago/Turabian StyleVictor Ciupină; Cristian P. Lungu; Eugeniu Vasile; Gabriel C. Prodan; Corneliu Porosnicu; Rodica Vladoiu; Aurelia Mandes; Virginia Dinca; Virginia Nicolescu; Madalina Prodan; Radu Manu. 2018. "Carbon-titanium multilayer films: Synthesis and characterization." AIP Conference Proceedings 2042, no. 1: 020034.
Carbon-Titan (C-Ti) multilayer films were deposited on silicon substrates by means of Thermionic Vacuum Arc (TVA) method. The final thickness of the multilayer structures was up to 400nm. The coated layers consisted of a base layer of about 100nm of Carbon deposited at low evaporation rates in order to ensure its stability on the substrate. Subsequently, seven Carbon and Titanium layers were deposited alternatively on top of Carbon base layer, each of them has a final thickness up to 40nm. For this study we obtained different batches of samples by variation of the substrate temperature between 0°C and 400°C, and the ion acceleration voltage applying a negative substrate bias voltage up to -700V . A low deposition rate 0.14nm/s for C and 0.18nm/s for Ti respectively was used in order to obtain the precise thickness. The characterization of microstructure properties of as prepared C-Ti multilayer structures were done using Electron Microscopy techniques (TEM, SEM, STEM), and Raman Spectroscopy. TEM and STEM studies were performed on Philips Tecnai F30G2 at 300kV setup. Identification of the structure of the material was based on the data obtained from diffraction pattern with a Philips CM120ST using CRISP2 application, with crystalline material module (ELD). The morphology and thickness of the samples were also determined by SEM techniques with Quanta FEG450 setup. The thickness thus measured are between 155.4nm and 393.9nm. Raman spectra were measured at room temperature on a Jobin Yvon T6400 spectrometer using 514.5nm line of an Ar+ laser as the excitation source. The measurements reveal the content of diamond-like sp3 and graphite-like sp2; the ratio sp3/sp2 increases when the bias voltage increases. For tribological characteristics determination, systematic measurements were performed using a ball-on-disk tribometer made by CSM Switzerland with normal force of 0.5, 1, 2, 3N respectively. The coefficient of friction depends on the substrate temperature and on the bias voltage. To characterize the electrical conductive properties, the electrical surface resistance versus temperature have been measured using drop voltage between two ohmic contacts on the sample and drop voltage on a standard resistance in a constant current regime. Owing to metallic layer of titanium in multilayer films, mechanical and electrical properties can be improved.
Victor Ciupina; Rodica Vladoiu; Cristian P. Lungu; Corneliu Porosnicu; Madalina Prodan; Aurelia Mandes; Virginia Dinca; Eugeniu Vasile; Ovidiu Cupsa; Virginia Nicolescu; Gabriel C. Prodan. Nanostructured carbon-titanium multilayer films obtained by thermionic vacuum arc method. Nanostructured Thin Films XI 2018, 10731, 1073107 .
AMA StyleVictor Ciupina, Rodica Vladoiu, Cristian P. Lungu, Corneliu Porosnicu, Madalina Prodan, Aurelia Mandes, Virginia Dinca, Eugeniu Vasile, Ovidiu Cupsa, Virginia Nicolescu, Gabriel C. Prodan. Nanostructured carbon-titanium multilayer films obtained by thermionic vacuum arc method. Nanostructured Thin Films XI. 2018; 10731 ():1073107.
Chicago/Turabian StyleVictor Ciupina; Rodica Vladoiu; Cristian P. Lungu; Corneliu Porosnicu; Madalina Prodan; Aurelia Mandes; Virginia Dinca; Eugeniu Vasile; Ovidiu Cupsa; Virginia Nicolescu; Gabriel C. Prodan. 2018. "Nanostructured carbon-titanium multilayer films obtained by thermionic vacuum arc method." Nanostructured Thin Films XI 10731, no. : 1073107.
A series of the multicomponent thin films (binary: Ti-C; Ti-Ag and ternary: Ti-C-Ag; Ti-C-Al) were fabricated by Thermionic Vacuum Arc (TVA) technology in order to study the wear resistance and the anticorrosion properties. The effects of Ti amount on the microstructure, tribological and morphological properties were subsequently investigated. TVA is an original deposition method using a combination of anodic arc and electron gun systems for the growth of films. The samples were characterized using scanning electron microscope (SEM) and a transmission electron microscope (TEM) accompanied by selected area electron diffraction (SAED). Tribological properties were studied by a ball-on-disc tribometer in the dry regime and the wettability was assessed by measuring the contact angle with the See System apparatus. Wear Rate results indicate an improved sliding wear behavior for Ti-C-Ag: 1.31 × 10−7 mm3/N m (F = 2 N) compared to Ti-C-Al coating wear rate: 4.24 × 10−7 mm3/N m. On the other hand, by increasing the normal load to 3 N an increase to the wear rate was observed for Ti-C-Ag: 2.58 × 10−5 mm3 compared to 2.33 × 10−6 mm3 for Ti-C-Al coating.
Aurelia Mandes; Rodica Vladoiu; Gabriel Prodan; Virginia Dinca; Corneliu Porosnicu; Paul Dinca. The Properties of Binary and Ternary Ti Based Coatings Produced by Thermionic Vacuum Arc (TVA) Technology. Coatings 2018, 8, 114 .
AMA StyleAurelia Mandes, Rodica Vladoiu, Gabriel Prodan, Virginia Dinca, Corneliu Porosnicu, Paul Dinca. The Properties of Binary and Ternary Ti Based Coatings Produced by Thermionic Vacuum Arc (TVA) Technology. Coatings. 2018; 8 (3):114.
Chicago/Turabian StyleAurelia Mandes; Rodica Vladoiu; Gabriel Prodan; Virginia Dinca; Corneliu Porosnicu; Paul Dinca. 2018. "The Properties of Binary and Ternary Ti Based Coatings Produced by Thermionic Vacuum Arc (TVA) Technology." Coatings 8, no. 3: 114.
Nano-sized Fe-based (metallic, carbidic and/or oxidic) [email protected] shell particles have been successfully synthesized in one step by the laser-induced pyrolysis method in an oxygen-deficient environment. The specific precursors were separately introduced through a three concentric nozzles injector: Fe(CO)5 vapors carried by C2H4 sensitizer (central flow), Zn(C2H5)2 vapors carried and diluted with Ar (middle annular coflow) and Ar containing low amount of O2 (external flow). Keeping constant the ethylene-carried Fe(CO)5 and O2 flows, while diminishing the Zn(C2H5)2 flow, we observed an increase of the Fe/Zn ratio in the resulted nanopowders. Also, using the same metal precursor flows, a nonlinear correlation between O2 external flow and nanocomposite atomic oxygen content is evidenced, indicating a possible interference of supplementary oxidation after air exposure. However, the lowest oxygen content along with metallic zinc was found in the sample synthesized in the most oxygen-deficient environment. Transmission electron microscopy (TEM), high-resolution electron microscopy (HRTEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDS), X-ray photoelectron spectroscopy (XPS) and magnetic analyses were performed for a comprehensive characterization. The aqueous [email protected] nanoparticles (NPs) suspensions were prepared using L-Dopa (l-3,4-dihydroxy-phenylalanine) as stabilizing agent in physiologic media. Also, a biocompatibility in vitro study was performed for PBS (phosphate buffered saline)-dispersed L-Dopa-stabilized [email protected] nanoparticles with the best core–shell structural features on both human normal lung fibroblasts and tumoral colorectal cells. Our results proved the ability of these newly synthesized nanostructures to target cancer cells in order to induce cytotoxicity and to exhibit biocompatibility on normal cells for maintaining the proper function of healthy tissue.
Lavinia Gavrila-Florescu; Florian Dumitrache; Mihaela Balas; Claudiu Teodor Fleaca; Monica Scarisoreanu; Iuliana P. Morjan; Elena Dutu; Alina Ilie; Ana-Maria Banici; Claudiu Locovei; Gabriel Prodan. Synthesis of Fe-based [email protected] shell nanopowders by laser pyrolysis for biomedical applications. Applied Physics B 2017, 123, 802 .
AMA StyleLavinia Gavrila-Florescu, Florian Dumitrache, Mihaela Balas, Claudiu Teodor Fleaca, Monica Scarisoreanu, Iuliana P. Morjan, Elena Dutu, Alina Ilie, Ana-Maria Banici, Claudiu Locovei, Gabriel Prodan. Synthesis of Fe-based [email protected] shell nanopowders by laser pyrolysis for biomedical applications. Applied Physics B. 2017; 123 (12):802.
Chicago/Turabian StyleLavinia Gavrila-Florescu; Florian Dumitrache; Mihaela Balas; Claudiu Teodor Fleaca; Monica Scarisoreanu; Iuliana P. Morjan; Elena Dutu; Alina Ilie; Ana-Maria Banici; Claudiu Locovei; Gabriel Prodan. 2017. "Synthesis of Fe-based [email protected] shell nanopowders by laser pyrolysis for biomedical applications." Applied Physics B 123, no. 12: 802.
We report the single-step synthesis of novel tin-based core–carbosilazane shell nano-composites using laser pyrolysis technique. Controlled NH3 flows were used to entrain the vapors of volatile precursors: Sn(CH3)4 (TMT) and Fe(CO)5 injected through center for the core and [Si(CH3)3]2NH (HMDS) through the annular nozzle for the shell. Both NH3 and HMDS plays also the role of absorbers of the IR laser radiation. The obtained nanoparticles shown polydispersity with sizes from 5 up to around 120 nm, having spheroidal crystalline core—disordered shell morphology as confirmed by transmission electron microscopy images, where also short amorphous nanofibers were observed. The dominant crystalline phase β-Sn (having mean crystallite size between 22 and 29 nm) and minor tin-iron intermetallic and nitride phases were identified by X-ray diffraction. Infrared spectra show the presence of Si–N and Si–C bonds, pointing to a carbosilazane composition of the shells, accompanied by Si–O bonds due to partial oxidation after air exposure. Three different samples were obtained by keeping constant the Sn and Fe precursors flows and diminishing the HDMS flow, together with the corresponding NH3 flows. Preliminary tests of these materials as anodes for Li-ion battery showed an initial discharge capacity near 800 mAg/h which decreased to 300 mAh/g after 20 cycles for the sample having the highest Sn content.
Claudiu Teodor Fleaca; Florian Dumitrache; Ion Sandu; Elena Dutu; Alina Ilie; Ana-Maria Banici; Eugeniu Vasile; Codruta Vlaic; Andreas Bund; Gabriel Prodan. Laser pyrolysis synthesis of Sn–Fe–[email protected] nanocomposites, characterization and evaluation as energy storage materials. Applied Physics A 2017, 123, 695 .
AMA StyleClaudiu Teodor Fleaca, Florian Dumitrache, Ion Sandu, Elena Dutu, Alina Ilie, Ana-Maria Banici, Eugeniu Vasile, Codruta Vlaic, Andreas Bund, Gabriel Prodan. Laser pyrolysis synthesis of Sn–Fe–[email protected] nanocomposites, characterization and evaluation as energy storage materials. Applied Physics A. 2017; 123 (11):695.
Chicago/Turabian StyleClaudiu Teodor Fleaca; Florian Dumitrache; Ion Sandu; Elena Dutu; Alina Ilie; Ana-Maria Banici; Eugeniu Vasile; Codruta Vlaic; Andreas Bund; Gabriel Prodan. 2017. "Laser pyrolysis synthesis of Sn–Fe–[email protected] nanocomposites, characterization and evaluation as energy storage materials." Applied Physics A 123, no. 11: 695.
The synthesis of Ag, Mg and Si nanocrystalline, embedded in a hydrogen-free amorphous carbon (a-C) matrix, deposited by a high vacuum and free buffer gas technique, were investigated. The films with compact structures and extremely smooth surfaces were prepared using the thermionic vacuum arc method in one electron gun configuration, on glass and silicon substrates. The surface morphology and wettability of the obtained multifunctional thin films were investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and free surface energy (FSE) by See System. The results from the TEM measurements show how the Ag, Mg and Si interacted with carbon and the influence these materials have on the thin film structure formation and the grain size distribution. SEM correlated with EDX results reveal a very precise comparative study, regarding the quantity of the elements that morphed into carbides nanostructures. Also, the FSE results prove how different materials in combination with carbon can make changes to the surface properties.
Virginia Dinca-Balan; Rodica Vladoiu; Aurelia Mandes; Gabriel Prodan. Correlation study of nanocrystalline carbon doped thin films prepared by a thermionic vacuum arc deposition technique. Journal of Physics D: Applied Physics 2017, 50, 435305 .
AMA StyleVirginia Dinca-Balan, Rodica Vladoiu, Aurelia Mandes, Gabriel Prodan. Correlation study of nanocrystalline carbon doped thin films prepared by a thermionic vacuum arc deposition technique. Journal of Physics D: Applied Physics. 2017; 50 (43):435305.
Chicago/Turabian StyleVirginia Dinca-Balan; Rodica Vladoiu; Aurelia Mandes; Gabriel Prodan. 2017. "Correlation study of nanocrystalline carbon doped thin films prepared by a thermionic vacuum arc deposition technique." Journal of Physics D: Applied Physics 50, no. 43: 435305.
Victor Ciupina; Eugeniu Vasile; Corneliu Porosnicu; Gabriel C. Prodan; Cristian P. Lungu; Rodica Vladoiu; Ionut Jepu; Aurelia Mandes; Virginia Dinca; Aureliana Caraiane; Virginia Nicolescu; Paul Dinca; Agripina Zaharia. Characterization of nitrogen doped silicon-carbon multi-layer nanostructures obtained by TVA method. Nanostructured Thin Films IX 2016, 992910 -992910-10.
AMA StyleVictor Ciupina, Eugeniu Vasile, Corneliu Porosnicu, Gabriel C. Prodan, Cristian P. Lungu, Rodica Vladoiu, Ionut Jepu, Aurelia Mandes, Virginia Dinca, Aureliana Caraiane, Virginia Nicolescu, Paul Dinca, Agripina Zaharia. Characterization of nitrogen doped silicon-carbon multi-layer nanostructures obtained by TVA method. Nanostructured Thin Films IX. 2016; ():992910-992910-10.
Chicago/Turabian StyleVictor Ciupina; Eugeniu Vasile; Corneliu Porosnicu; Gabriel C. Prodan; Cristian P. Lungu; Rodica Vladoiu; Ionut Jepu; Aurelia Mandes; Virginia Dinca; Aureliana Caraiane; Virginia Nicolescu; Paul Dinca; Agripina Zaharia. 2016. "Characterization of nitrogen doped silicon-carbon multi-layer nanostructures obtained by TVA method." Nanostructured Thin Films IX , no. : 992910-992910-10.
Highlights•Three facile routes for synthesis of MAA-functionalized CdS nanoparticles.•Morphology of CdS nanoparticles was studied by XRD and TEM.•Optical, photoluminescence and photocatalytic properties were investigated.•A very efficient photocatalyst was obtained by chemical precipitation. AbstractThe functionalized nanomaterials, including II-VI semiconductors, have many interesting properties and applications, generally superior to those of pristine nanomaterials. Cadmium sulfide nanoparticles functionalized with mercaptoacetate were prepared by one-pot synthesis, using three strategies. The structure and morphology of the obtained nanopowders were studied by X-ray diffraction and transmission electron microscopy. The optical properties were investigated by UV–Visible diffuse reflectance spectroscopy and the band gap energy values based on Tauc equation were determined. The catalytic activity of functionalized cadmium sulfide nanopowders, evaluated in the degradation of an azoic dye, was correlated with the synthesis route, particle size, photoluminescence and specific surface area.
Anca Dumbrava; Daniela Berger; Gabriel Prodan; Florin Moscalu; Aurel Diacon. Facile synthesis, characterization and application of functionalized cadmium sulfide nanopowders. Materials Chemistry and Physics 2016, 173, 70 -77.
AMA StyleAnca Dumbrava, Daniela Berger, Gabriel Prodan, Florin Moscalu, Aurel Diacon. Facile synthesis, characterization and application of functionalized cadmium sulfide nanopowders. Materials Chemistry and Physics. 2016; 173 ():70-77.
Chicago/Turabian StyleAnca Dumbrava; Daniela Berger; Gabriel Prodan; Florin Moscalu; Aurel Diacon. 2016. "Facile synthesis, characterization and application of functionalized cadmium sulfide nanopowders." Materials Chemistry and Physics 173, no. : 70-77.
Ionized nitrogen doped Si-C thin films at 200°C substrate temperature were obtained by Thermionic Vacuum Arc (TVA) method. To increase the energy of N, C and Si ions, -400V, -600V and -1000V negative bias voltages was applied on the substrate. The 400nm, 600nm and 1000nm N-SiC coatings on glass was deposed. To characterize the structure of as-prepared N-SiC coatings, Transmission Electron Microscopy (TEM), High Resolution Transmission Electron Microscopy (HRTEM), X-Ray and Photoelectron Spectroscopy (XPS) techniques was performed. Electrical conductivity was measured comparing the potential drop on the structure with the potential drop on a series standard resistance in a constant current mode. To justify the dependence of measured electrical conductivity by the temperature, we assume a thermally activated electrical transport mechanism.
Victor Ciupina; Cristian P. Lungu; Rodica Vladoiu; Gabriel C. Prodan; Stefan Antohe; Corneliu Porosnicu; Iuliana Stanescu; Ionut Jepu; Sorina Iftimie; Marius Belc; Aurelia Mandes; Virginia Dinca; Eugeniu Vasile; Valeriu Zarovski; Virginia Nicolescu; Aureliana Caraiane. Structural and electrical properties of N doped SiC nanostructures obtained by TVA method. Nanostructured Thin Films VIII 2015, 9558, 955808 .
AMA StyleVictor Ciupina, Cristian P. Lungu, Rodica Vladoiu, Gabriel C. Prodan, Stefan Antohe, Corneliu Porosnicu, Iuliana Stanescu, Ionut Jepu, Sorina Iftimie, Marius Belc, Aurelia Mandes, Virginia Dinca, Eugeniu Vasile, Valeriu Zarovski, Virginia Nicolescu, Aureliana Caraiane. Structural and electrical properties of N doped SiC nanostructures obtained by TVA method. Nanostructured Thin Films VIII. 2015; 9558 ():955808.
Chicago/Turabian StyleVictor Ciupina; Cristian P. Lungu; Rodica Vladoiu; Gabriel C. Prodan; Stefan Antohe; Corneliu Porosnicu; Iuliana Stanescu; Ionut Jepu; Sorina Iftimie; Marius Belc; Aurelia Mandes; Virginia Dinca; Eugeniu Vasile; Valeriu Zarovski; Virginia Nicolescu; Aureliana Caraiane. 2015. "Structural and electrical properties of N doped SiC nanostructures obtained by TVA method." Nanostructured Thin Films VIII 9558, no. : 955808.
Rodica Vladoiu; Aurelia Mandes; Virginia Dinca Balan; Gabriel Prodan; Pavel Kudrna; Milan Tichy. Magnesium plasma diagnostics by heated probe and characterization of the Mg thin films deposited by thermionic vacuum arc technology. Plasma Sources Science and Technology 2015, 24, 1 .
AMA StyleRodica Vladoiu, Aurelia Mandes, Virginia Dinca Balan, Gabriel Prodan, Pavel Kudrna, Milan Tichy. Magnesium plasma diagnostics by heated probe and characterization of the Mg thin films deposited by thermionic vacuum arc technology. Plasma Sources Science and Technology. 2015; 24 (3):1.
Chicago/Turabian StyleRodica Vladoiu; Aurelia Mandes; Virginia Dinca Balan; Gabriel Prodan; Pavel Kudrna; Milan Tichy. 2015. "Magnesium plasma diagnostics by heated probe and characterization of the Mg thin films deposited by thermionic vacuum arc technology." Plasma Sources Science and Technology 24, no. 3: 1.
Crystalline Si-C thin films were prepared at substrate temperature between 200°C and 1000°C using Thermionic Vacuum Arc (TVA) method. To increase the acceleration potential drop a negative bias voltage up to -1000V was applied on the substrate. The 200nm thickness carbon thin films was deposed on glass and Si substrate and then 200-500 nm thickness Si-C layer on carbon thin films was deposed. Transmission Electron Microscopy (TEM), High Resolution Transmission Electron Microscopy (HRTEM), X-Ray Photoelectron Spectroscopy (XPS), and electrical conductivity measurement technique characterized the structure and physical characteristics of as-prepared SiC coating. At a constant acceleration potential drop, the electrical conductivity of the Si-C films deposed on C, increase with increasing of substrate temperature. On the other part, significant increases in the acceleration potential drop at constant substrate temperature lead to a variation of the crystallinity and electrical conductivity of the SiC coatings XPS analysis was performed using a Quantera SXM equipment, with monochromatic AlKα radiation at 1486.6eV. Electrical conductivity of the Si-C coating on carbon at different temperatures was measured comparing the potential drop on the sample with the potential drop on a series standard resistance in constant mode.
Victor Ciupina; Cristian P. Lungu; Rodica Vladoiu; Gabriel C. Prodan; Stefan Antohe; Corneliu Porosnicu; Iuliana Stanescu; Ionut Jepu; Sorina Iftimie; Madalina Prodan; Aurelia Mandes; Virginia Dinca; Eugeniu Vasile; Valeriu Zarovski; Virginia Nicolescu. The effect of the substrate temperature and the acceleration potential drop on the structural and physical properties of SiC thin films deposed by TVA method. Nanostructured Thin Films VII 2014, 9172, 91720Y .
AMA StyleVictor Ciupina, Cristian P. Lungu, Rodica Vladoiu, Gabriel C. Prodan, Stefan Antohe, Corneliu Porosnicu, Iuliana Stanescu, Ionut Jepu, Sorina Iftimie, Madalina Prodan, Aurelia Mandes, Virginia Dinca, Eugeniu Vasile, Valeriu Zarovski, Virginia Nicolescu. The effect of the substrate temperature and the acceleration potential drop on the structural and physical properties of SiC thin films deposed by TVA method. Nanostructured Thin Films VII. 2014; 9172 ():91720Y.
Chicago/Turabian StyleVictor Ciupina; Cristian P. Lungu; Rodica Vladoiu; Gabriel C. Prodan; Stefan Antohe; Corneliu Porosnicu; Iuliana Stanescu; Ionut Jepu; Sorina Iftimie; Madalina Prodan; Aurelia Mandes; Virginia Dinca; Eugeniu Vasile; Valeriu Zarovski; Virginia Nicolescu. 2014. "The effect of the substrate temperature and the acceleration potential drop on the structural and physical properties of SiC thin films deposed by TVA method." Nanostructured Thin Films VII 9172, no. : 91720Y.
Binary elemental plasma of carbon and silver was synthesized using the thermionic vacuum arc technology for the first time in this configuration. The structural investigations of the deposited silver/amorphous carbon (Ag/a-C) nanocomposites thin film on different materials, such as Si, glass, and stainless steel OLC 45 substrates performed by high-resolution transmission electron microscopy were reported, as well as the modification of the properties at the nanometer level.
Aurelia Mandes; Rodica Vladoiu; Virginia Dinca; Gabriel Prodan. Binary C-Ag Plasma Breakdown and Structural Characterization of the Deposited Thin Films by Thermionic Vacuum Arc Method. IEEE Transactions on Plasma Science 2014, 42, 2806 -2807.
AMA StyleAurelia Mandes, Rodica Vladoiu, Virginia Dinca, Gabriel Prodan. Binary C-Ag Plasma Breakdown and Structural Characterization of the Deposited Thin Films by Thermionic Vacuum Arc Method. IEEE Transactions on Plasma Science. 2014; 42 (10):2806-2807.
Chicago/Turabian StyleAurelia Mandes; Rodica Vladoiu; Virginia Dinca; Gabriel Prodan. 2014. "Binary C-Ag Plasma Breakdown and Structural Characterization of the Deposited Thin Films by Thermionic Vacuum Arc Method." IEEE Transactions on Plasma Science 42, no. 10: 2806-2807.
Mihai Cosmin Corobea; Ignac Capek; Raluca Ianchis; Dan Donescu; Raluca Somoghi; Marius Ghiurea; Cristina Lavinia Nistor; Violeta Purcar; Ludmila Otilia Cinteza; Constantin Radovici; Gabriel Prodan. Silica nanowires obtained on clay mineral layers and their influence on mini-emulsion polymerisation. Applied Clay Science 2014, 95, 232 -242.
AMA StyleMihai Cosmin Corobea, Ignac Capek, Raluca Ianchis, Dan Donescu, Raluca Somoghi, Marius Ghiurea, Cristina Lavinia Nistor, Violeta Purcar, Ludmila Otilia Cinteza, Constantin Radovici, Gabriel Prodan. Silica nanowires obtained on clay mineral layers and their influence on mini-emulsion polymerisation. Applied Clay Science. 2014; 95 ():232-242.
Chicago/Turabian StyleMihai Cosmin Corobea; Ignac Capek; Raluca Ianchis; Dan Donescu; Raluca Somoghi; Marius Ghiurea; Cristina Lavinia Nistor; Violeta Purcar; Ludmila Otilia Cinteza; Constantin Radovici; Gabriel Prodan. 2014. "Silica nanowires obtained on clay mineral layers and their influence on mini-emulsion polymerisation." Applied Clay Science 95, no. : 232-242.
Victor Ciupina; Cristian Petrica Lungu; Rodica Vladoiu; Gabriel Prodan; Corneliu Porosnicu; Marius Belc; Iuliana M. Stanescu; Eugeniu Vasile; Razvan Rughiniş. Silicon carbide multilayer protective coating on carbon obtained by thermionic vacuum arc method. Journal of Nanophotonics 2014, 8, 83996 .
AMA StyleVictor Ciupina, Cristian Petrica Lungu, Rodica Vladoiu, Gabriel Prodan, Corneliu Porosnicu, Marius Belc, Iuliana M. Stanescu, Eugeniu Vasile, Razvan Rughiniş. Silicon carbide multilayer protective coating on carbon obtained by thermionic vacuum arc method. Journal of Nanophotonics. 2014; 8 (1):83996.
Chicago/Turabian StyleVictor Ciupina; Cristian Petrica Lungu; Rodica Vladoiu; Gabriel Prodan; Corneliu Porosnicu; Marius Belc; Iuliana M. Stanescu; Eugeniu Vasile; Razvan Rughiniş. 2014. "Silicon carbide multilayer protective coating on carbon obtained by thermionic vacuum arc method." Journal of Nanophotonics 8, no. 1: 83996.
SiC single-layer or multi-layer on C used to improve the oxidation resistance and tribological properties of C have been obtained by Thermionic Vacuum Arc (TVA) method. The 200nm thickness carbon thin films was deposed on glass or Si substrate and then 100÷500 nm thickness SiC successively layers on carbon thin film was deposed. The microstructure and mechanical characteristics of as-prepared SiC coating were investigated by Transmission Electron Microscopy (TEM, STEM), Energy Dispersive X-Ray Spectroscopy (EDS), Electron Scattering Chemical Analysis (ESCA) and tribological techniques. Samples containing SiC single-layer or multi-layer coating on carbon were investigated up to 1000°C. The results of thermal treatments reveals the increase of oxidation resistance with increase of the number of SiC layers. The mechanism of oxidation protection is based on the reaction between SiC and elemental oxygen resulting SiO2 and CO. The tribological behavior of SiC coatings was evaluated with a tribometer with ball-on-disk configuration from CSM device with 6mm diameter sapphire ball, sliding speed in dry conditions being 0.2m/s, with normal contact loads of 0.5N, 1N, 1.5N and 2N, under unlubricated conditions. The friction coefficient on SiC was compared with the friction coefficient on uncoated carbon layer. Electrical surface resistance of SiC coating on carbon at different temperatures was measured comparing the potential drop on the sample with the potential drop on a series standard resistance in constant mode.
V. Ciupina; C. P. Lungu; R. Vladoiu; T-D. Epure; G. Prodan; C. Rosca; C. Porosnicu; I. Jepu; M. Belc; M. Prodan; I. M. Stanescu; C. Stefanov; M. Contulov; A. Mandes; V. Dinca; Eugeniu Vasile; V. Zarovschi; V. Nicolescu. SiC multi-layer protective coating on carbon obtained by thermionic vacuum arc method. Nanostructured Thin Films VI 2013, 8818, 881807 .
AMA StyleV. Ciupina, C. P. Lungu, R. Vladoiu, T-D. Epure, G. Prodan, C. Rosca, C. Porosnicu, I. Jepu, M. Belc, M. Prodan, I. M. Stanescu, C. Stefanov, M. Contulov, A. Mandes, V. Dinca, Eugeniu Vasile, V. Zarovschi, V. Nicolescu. SiC multi-layer protective coating on carbon obtained by thermionic vacuum arc method. Nanostructured Thin Films VI. 2013; 8818 ():881807.
Chicago/Turabian StyleV. Ciupina; C. P. Lungu; R. Vladoiu; T-D. Epure; G. Prodan; C. Rosca; C. Porosnicu; I. Jepu; M. Belc; M. Prodan; I. M. Stanescu; C. Stefanov; M. Contulov; A. Mandes; V. Dinca; Eugeniu Vasile; V. Zarovschi; V. Nicolescu. 2013. "SiC multi-layer protective coating on carbon obtained by thermionic vacuum arc method." Nanostructured Thin Films VI 8818, no. : 881807.
We investigated the growth and structure properties of C-Mg thin films obtained for the first time by Thermionic Vacuum Arc (TVA) deposition. The TVA technology is suitable for producing nanostructured materials because of the high power density of the vapor plasma generated by accelerated electron flux from the cathode and high energy of the ions incident on the depositing film, both these properties ensuring a high dispersion of the evaporated material. The properties of the deposited C-Mg thin films were investigated in terms of wettability and morphology. The surface free energy (SFE) was determined by means of Surface Energy Evaluation System (See System) indicating a hydrophobic character and the morphology were determined from BF-TEM image performed by Philips CM 120 ST TEM system.
Aurelia Mandes; Rodica Vladoiu; Virginia Dinca; Gabriel Prodan. Growth and Characterization of the High Purity C-Mg Thin Films Obtained by Thermionic Vacuum Arc (TVA) Technology. Advanced Materials Research 2013, 816-817, 106 -110.
AMA StyleAurelia Mandes, Rodica Vladoiu, Virginia Dinca, Gabriel Prodan. Growth and Characterization of the High Purity C-Mg Thin Films Obtained by Thermionic Vacuum Arc (TVA) Technology. Advanced Materials Research. 2013; 816-817 ():106-110.
Chicago/Turabian StyleAurelia Mandes; Rodica Vladoiu; Virginia Dinca; Gabriel Prodan. 2013. "Growth and Characterization of the High Purity C-Mg Thin Films Obtained by Thermionic Vacuum Arc (TVA) Technology." Advanced Materials Research 816-817, no. : 106-110.
We studied the influence of the synthesis route on the morphology and optical properties of zinc oxide (ZnO), with applications in dye-sensitized solar cells (DSSCs). For this purpose, we obtained surfactant capped ZnO nanopowders, in the presence of non-ionic surfactants with different structures, and demonstrated their behavior as semiconductors in DSSCs. The ZnO nanopowders and films (obtained from nanopowders using the doctor blading method) were analyzed by transmission electron microscopy (TEM), high resolution TEM (HRTEM), and selected area electron diffraction (SAED). The optical properties were examined by UV, visible spectroscopy, and the band gap energies were calculated using the Tauc equation. The values obtained for DSSCs efficiencies were in good agreement with the characteristics of ZnO, both powders and films, and can be correlated with the synthesis route. The highest efficiency (1.19%) was achieved using ZnO nanopowder capped with Triton X-100, having a mean diameter of ∼19 nm. We find that the use of capped ZnO nanoparticles is favorable for DSSCs, possibly because of the good porosity of the film and better dye adsorption. Moreover, the efficiency of the cells is influenced by the surfactant structure, due to the particle morphology.
Anca Dumbrava; Gabriel Prodan; Florin Moscalu. Investigations on the influence of surfactant in morphology and optical properties of zinc oxide nanopowders for dye-sensitized solar cells applications. Materials Science in Semiconductor Processing 2013, 16, 1095 -1104.
AMA StyleAnca Dumbrava, Gabriel Prodan, Florin Moscalu. Investigations on the influence of surfactant in morphology and optical properties of zinc oxide nanopowders for dye-sensitized solar cells applications. Materials Science in Semiconductor Processing. 2013; 16 (4):1095-1104.
Chicago/Turabian StyleAnca Dumbrava; Gabriel Prodan; Florin Moscalu. 2013. "Investigations on the influence of surfactant in morphology and optical properties of zinc oxide nanopowders for dye-sensitized solar cells applications." Materials Science in Semiconductor Processing 16, no. 4: 1095-1104.