National Institute Of Materials Physics - Romania

Publications

5975 articles found

1751. CHARACTERIZATION OF CdS-DOPED GLASS FILMS OBTAINED BY PULSED LASER DEPOSITION

Authors: Iordanescu, CR; Elisa, M; Epurescu, G; Filipescu, M; Enculescu, M; Monteiro, RCC; Constantin, L

Published: 2017, REVISTA ROMANA DE MATERIALE-ROMANIAN JOURNAL OF MATERIALS, 47, 65, DOI:

In the present work we study the optical, struc-tural and morphological properties of CdS-doped glass films, deposited by Pulsed Laser Deposition (PLD) method. The glass target used for ablation was prepared by conventional melt-quenching technique and the semiconductor dopant, CdS powder, was embedded in the borosilicate melt glass host by continuous stirring. In order to improve the properties of the films, the laser wavelength was modified. Photoluminescence emission (PL) of CdSdoped glass films revealed a broad band located in the visible range. The structural analysis was carried out by micro-Raman spectroscopy, pointing out specific vibration modes for Si-O-Si bonds as well as for CdS dopant. The morphology and the chemical characterization of the films were investigated by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX) and Atomic Force Microscopy (AFM).

1752. Gas sensing properties of NiO/mesoporous SnO2

Authors: Stanoiu, A; Somacescu, S; Simion, CE; Calderon-Moreno, JM; Florea, OG

Published: 2017, 2017 INTERNATIONAL SEMICONDUCTOR CONFERENCE (CAS), 40TH EDITION, 96, DOI:

NiO/mesoporous SnO2 was deposited by incipient wetness impregnation of the SnO2 powder prepared by hydrothermal synthesis route templated by Brij (R) 35. The sensing properties were acquired and the dependence on the operating temperature of the sensitive material was pointed out. Sensitive selectivity towards H2S detection was highlighted at 350 degrees C.

1753. ONE SIDE POLYANILINE COATED FIBERS BASED ACTUATOR

Authors: Beregoi, M; Evanghelidis, A; Ganea, P; Iovu, H; Matei, E; Enculescu, I

Published: 2017, UNIVERSITY POLITEHNICA OF BUCHAREST SCIENTIFIC BULLETIN SERIES B-CHEMISTRY AND MATERIALS SCIENCE, 79, 130, DOI:

In this study, one side aligned PANI coated micro-fibers were fabricated in order to develop a novel actuator configuration. Thus, electrospun PMMA fibers were coated only on one side with a thin gold layer guiding in this way the deposition of PANI (only on the side with gold considering an adequate PANI deposition time). Further, the half-metalized fibers were employed as working microelectrodes for electrochemical deposition of PANI. The prepared PANI coated fibers present actuation properties when they are in contact with an electrolyte like 1 M H2SO4. By switching the potential between +1.4 and -0.2 V, the fiber strips move due to the swelling/shrinking and anisotropic deposition of PANI film.

1754. Structural and Antimicrobial Evaluation of Silver Doped Hydroxyapatite- Polydimethylsiloxane Thin Layers

Authors: Iconaru, SL; Chifiriuc, MC; Groza, A

Published: 2017, JOURNAL OF NANOMATERIALS, 2017, DOI: 10.1155/2017/7492515

An Ag:HAp (x(Ag) = 0.5) powder was deposited by thermal evaporation technique as coating on a silicon substrate previously covered with a polydimethylsiloxane (PDMS) layer. The Ag: HAp-PDMS layers were characterized by Scanning ElectronMicroscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and Fourier Transform Infrared Spectroscopy (FT-IR). By infrared spectroscopy analysis, the phase composition of the Ag: HAp-PDMS layers was investigated. The antimicrobial activity of Ag: HAp-PDMS layers was tested against Escherichia coli, Staphylococcus aureus, and Candida albicans microbial strains. The microbial activity decreases significantly for the surveyed time intervals on Ag: HAp-PDMS layers.

1755. Light illumination effects on floating gate memory with Ge nanocrystals in HfO2

Authors: Palade, C; Slav, A; Lepadatu, AM; Lazanu, S; Ciurea, ML; Stoica, T

Published: 2017, 2017 INTERNATIONAL SEMICONDUCTOR CONFERENCE (CAS), 40TH EDITION, 90, DOI:

The influence of light illumination on the programming of a capacitor floating gate memory based on Ge nanocrystals in HfO2 was studied. The capacitor was fabricated on a c-Si substrate by magnetron sputtering deposition of a layer sequence of HfO2/Ge-HfO2/HfO2 and post-growth rapid thermal annealing for nanocrystals formation at 600 degrees C. The illumination of the structure was performed through a semi-transparent Au contact (20% transparency). A maximum value of the light- induced change of 90% in C-V curve was obtained for 5 mW/cm(2) illumination during +5 V writing programming. The effect of the light exposure on the relative change of the C-V curve can be increased by reducing the writing time at 1 min.

1756. WETTABILITY BY WATER CONTACT ANGLE UPON THE SURFACE OF WOOL FABRICS COVERED WITH OXIDE NANOPARTICLES

Authors: Birzu, M; Frunza, L; Zgura, I; Cotorobai, VF; Ganea, CP; Preda, N; Enculescu, M

Published: JUL-SEP 2017, DIGEST JOURNAL OF NANOMATERIALS AND BIOSTRUCTURES, 12, 931, DOI:

Wetting properties of wool textiles were studied either for the raw samples or for those functionalized via covering them at low temperature with nanoparticles of titanium dioxide or zinc oxide. Oxygen plasma pretreatment was performed before deposition. Characterization used optical examination, scanning electron microscopy, infrared spectroscopy, thermogravimetry, X-ray diffraction. Wetting properties were tested under static conditions by estimating the water contact angle. The sessile drop method was applied. The deposited matter represents 3 to 8 wt%, covering rather uniformly the fiber surface. Treated samples show mostly lower values of contact angle than the pristine ones. Cassie-Baxter model is discussed in relation to the equilibrium contact angle of the support.

1757. MEASUREMENT OF CHARGE CARRIER MOBILITY IN PEROVSKITE NANOWIRE FILMS BY PHOTO-CELIV METHOD

Authors: Aukstuolis, A; Girtan, M; Mousdis, GA; Mallet, R; Socol, M; Rasheed, M; Stanculescu, A

Published: JAN-MAR 2017, PROCEEDINGS OF THE ROMANIAN ACADEMY SERIES A-MATHEMATICS PHYSICS TECHNICAL SCIENCES INFORMATION SCIENCE, 18, 41, DOI:

In this paper the holes' mobility for the configuration FTO/TiO2/CH3NH3PbI3/SpiroMeOTAD/Au was measured for the first time by the Photo-CELIV method. The TiO2 dense film was deposited by reactive sputtering at room temperature on FTO glass substrates. High crystalized perovskite films were deposited from solutions in one step by spin coating. Spiro-MeOTAD molecular glass was used as holes transporting layer. The highest holes' mobility from TiO2 thin film through the perovskite and Spiro MeOTAD film to the top gold electrode was of Order 8.5x10(-7) cm(2)/Vs.

1758. PHOTOACTIVITY OF HEMATITE ELECTRODE PREPARED VIA ANODIC ELECTRODEPOSITION ON FTO AND FTO/TiO2 SUBSTRATES

Authors: Sima, M; Vasile, E; Sima, MA

Published: JUL-SEP 2017, DIGEST JOURNAL OF NANOMATERIALS AND BIOSTRUCTURES, 12, 758, DOI:

The hematite films were prepared via anodic electrodeposition on FTO and FTO/mesoporous TiO2 substrates. The hematite photoanodes were characterized by X-ray diffraction and scanning electron microscopy. The performance of the prepared hematite photoanodes was assessed based on photocurrent-voltage curves and electrochemical impedance spectra. The modification of the hematite surface with nickel oxide nanoparticles improved the performance of the hematite photoanode while phosphorous doped hematite photoanode shows poor photoactivity. The onset of water oxidation photocurrent was cathodically shifted for hematite photoanodes prepared on FTO/TiO2 substrate.

1759. MAPLE DEPOSITION OF PLGA MICROSPHERES FOR MEDICAL APPLICATIONS

Authors: Fufa, O; Socol, M; Preda, N; Grigorescu, S; Croitoru, S; Socol, G

Published: JAN-MAR 2017, DIGEST JOURNAL OF NANOMATERIALS AND BIOSTRUCTURES, 12, 80, DOI:

The aim of our study was to synthesize and evaluate the physicochemical and biological properties of composite films based on poly(lactic-co-glycolic acid) copolymer and quercetin (PLGA/Q) microspheres. During our experiments, we firstly synthesized the PLGA/Q microspheres by using an oil-in-water emulsion-diffusion-evaporation method. Subsequently, the as-prepared composite material was subjected to the matrix assisted pulsed laser evaporation (MAPLE) technique, in order to obtain the PLGA/Q coatings. Relevant compositional and microstructural features of the synthesized samples were obtained by means of Fourier transform infrared spectroscopy (FTIR) and AFM (atomic force microscopy). The long-term biocompatibility of the synthesized films was in vitro evaluated by cellular viability and immunofluorescence assays.

1760. Epitaxial La0.67Ba0.33Ti0.02Mn0.98 O-3 oxide thin films

Authors: Marouan, O; Galca, AC

Published: 2017, ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES, 73, C222, DOI: 10.1107/S2053273317093512