Number of found documents: 482
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Souhrnný report výsledků smluvního výzkumu mezi FZU AV ČR, v.v. i. a HVM Plasma s.r.o. za rok 2016
Mates, Tomáš; Fejfar, Antonín; Ledinský, Martin; Vetushka, Aliaksi; Pikna, Peter; Bauerová, Pavla
2017 - Czech
Několika diagnostickými metodami byly zkoumány vzorky ochranných vrstev na bázi DLC (Diamond-like-Carbon) na různých substrátech (testovací tělíska i reálné součástky). Pomocí Ramanovské spektroskopie byly vyhodnocovány vazby ve vzorcích pro bližší určení strukturních variací a povrchových modifikací, a to jak pro čerstvě připravené vzorky, tak zejména pro vzorky které prošly různými zátěžovými testy.\nSkenovacím elektronovým mikroskopem (SEM) byla zkoumána povrchová struktura vrstev v různých místech vzorků a vyhledávána vhodná testovací místa pro následnou analýzu pomocí Mikroskopu atomárních sil (AFM). Mikroskopem AFM ve speciálních režimech byly měřeny mapy lokálních mechanických vlastností (tření, adheze hrotu, disipace energie, atd.). Na vybraném vzorku byla metodou Focussed Ion Beam (FIB) analyzována struktura průřezu vzorku a dále bylo zdokumentováno prvkové složení v různých tloušťkách vrstvy metodou Energy-dispersive X-ray Spectroscopy (EDS).\n Samples of protective layers based on DLC (Diamond-like-Carbon) on different substrates (test bodies and real components) were studied by several diagnostic methods.\nRaman spectroscopy was used for the detection of bindings in order to specify the structural variations, surface modifications both for as-deposited samples and particularly for samples that underwent different stress tests.\nScanning Electron Microscope (SEM) was used to examine the surface structure of layers in different locations on the sample and to search suitable test spots for the subsequent analysis by the Atomic Force Microscope (AFM). AFM in special modes was employed to measure the maps local mechanical properties (friction, tip adhesion, energy dissipation, etc.).\nOn a selected sample, the cross-sectional structure of the sample was analysed by the Focussed Ion Beam (FIB) and the elemental composition in various thicknesses was documented by the Energy-dispersive X-ray Spectroscopy (EDS).\n Keywords: diamond like carbon layers; Raman spectroscopy; Atomic Force Microscopy; Scanning Electron Microscopy; Focussed Ion Beam; Energy Dispersive Spectroscopy Available at various institutes of the ASCR
Souhrnný report výsledků smluvního výzkumu mezi FZU AV ČR, v.v. i. a HVM Plasma s.r.o. za rok 2016

Několika diagnostickými metodami byly zkoumány vzorky ochranných vrstev na bázi DLC (Diamond-like-Carbon) na různých substrátech (testovací tělíska i reálné součástky). Pomocí Ramanovské spektroskopie ...

Mates, Tomáš; Fejfar, Antonín; Ledinský, Martin; Vetushka, Aliaksi; Pikna, Peter; Bauerová, Pavla
Fyzikální ústav, 2017

Characterization and tribological testing of a carbon-based nanolayer prepared by ion beam assisted deposition
Horažďovský, T.; Kovač, J.; Drbohlav, Ivo
2017 - English
Carbon-based nanolayers have been attracting much attention due to their excellent low-friction properties, their high hardness and their good wear resistance. In this work we present the results of material research aimed at reducing the friction of the functional surfaces of titanium implants, and thus extending their lifetime to reoperation. An analysis of the chemical composition showed that the modified surface is composed of a carbon-based nanolayer, a mixed interface, and a nitrogen-enriched sublayer. Raman spectroscopy showed the DLC character of the carbon-based nanolayer with sp2 rich bonds. A TiN compound was detected by X-ray diffraction in the modified surface area.\n Keywords: nanolayer; friction; nanohardness Available at various institutes of the ASCR
Characterization and tribological testing of a carbon-based nanolayer prepared by ion beam assisted deposition

Carbon-based nanolayers have been attracting much attention due to their excellent low-friction properties, their high hardness and their good wear resistance. In this work we present the results of ...

Horažďovský, T.; Kovač, J.; Drbohlav, Ivo
Fyzikální ústav, 2017

Mechanical properties of Cr-DLC layers prepared by hybrid laser technology
Písařík, Petr; Jelínek, Miroslav; Remsa, J.; Tolde, Z.
2017 - English
Diamond like carbon (DLC) layers have excellent biological properties for use in medicine for coating implants, but poor adhesion to biomedical alloys (titanium alloys, chromium alloys and stainless steel). The adhesion can be improved by doping the DLC layer by chromium, as described in this article. Chromium doped diamond like carbon layers (Cr DLC) were deposited by hybrid deposition system using KrF excimer laser (deposition diamond like carbon - graphite target) and\nmagnetron sputtering (deposition chromium - chromium target). Carbon and chromium contents were determined by wavelength dispersive X-ray spectroscopy.\n Keywords: DLC; chromium doped; mechanical properties; PLD Available at various institutes of the ASCR
Mechanical properties of Cr-DLC layers prepared by hybrid laser technology

Diamond like carbon (DLC) layers have excellent biological properties for use in medicine for coating implants, but poor adhesion to biomedical alloys (titanium alloys, chromium alloys and stainless ...

Písařík, Petr; Jelínek, Miroslav; Remsa, J.; Tolde, Z.
Fyzikální ústav, 2017

Correlated microscopy of electronic and material properties of graphene grown on diamond thin films
Rezek, Bohuslav; Čermák, Jan; Varga, Marián; Tulic, S.; Skákalová, V.; Waitz, T.; Kromka, Alexander
2017 - English
In this work we compare growth of graphene on diamond thin films that enable large area processing. We use films with different crystal size and surface roughness to obtain deeper insight into formation and properties of GoD. The diamond films are coated by a nm thin sputtered Ni layer and heated to 900°C in a forming gas atmosphere (H2/Ar) to initiate catalytic thermal CVD process. The samples are cleaned from residual Ni after the growth process. We employ scanning electron microscopy, Raman micro-spectroscopy and Kelvin probe force microscopy to correlate material, structural, and electronic properties of graphene on diamond. We show how grain size and grain boundaries influence graphene growth and material and electronic properties. For instance we show that the grain boundaries (with non-diamond carbon phases) in diamond films have an important role. They influence the electronic properties and they are beneficial for forming graphene on diamond higher quality. Keywords: graphene; diamond; microscopy; micro-spectroscopy; electronic properties Available at various institutes of the ASCR
Correlated microscopy of electronic and material properties of graphene grown on diamond thin films

In this work we compare growth of graphene on diamond thin films that enable large area processing. We use films with different crystal size and surface roughness to obtain deeper insight into ...

Rezek, Bohuslav; Čermák, Jan; Varga, Marián; Tulic, S.; Skákalová, V.; Waitz, T.; Kromka, Alexander
Fyzikální ústav, 2017

The intrinsic submicron ZnO thin films prepared by reactive magnetron sputtering
Remeš, Zdeněk; Stuchlík, Jiří; Purkrt, Adam; Chang, Yu-Ying; Jirásek, Vít; Štenclová, Pavla; Prajzler, V.; Nekvindová, P.
2017 - English
The DC reactive magnetron sputtering of metallic target in oxide atmosphere is a simple method of depositing the intrinsic (undoped) nanocrystalline layers of metal oxides. We have optimized the deposition of the intrinsic ZnO thin films with submicron thickness 50−500 nm on fused silica glass substrates and investigated the localized defect states below the optical absorption edge down to 0.01 % using photothermal deflection spectroscopy from UV to IR. We have shown that the defect density, the optical absorptance and the related optical attenuation in planar waveguides can be significantly reduced by annealing in air at 400 °C. Keywords: ZnO; reactive magnetron sputtering; plasma treatment; photothermal deflection spectroscopy; optical spectroscopy Available at various institutes of the ASCR
The intrinsic submicron ZnO thin films prepared by reactive magnetron sputtering

The DC reactive magnetron sputtering of metallic target in oxide atmosphere is a simple method of depositing the intrinsic (undoped) nanocrystalline layers of metal oxides. We have optimized the ...

Remeš, Zdeněk; Stuchlík, Jiří; Purkrt, Adam; Chang, Yu-Ying; Jirásek, Vít; Štenclová, Pavla; Prajzler, V.; Nekvindová, P.
Fyzikální ústav, 2017

Hydrogen plasma treatment of ZnO thin films
Chang, Yu-Ying; Neykova, Neda; Stuchlík, Jiří; Purkrt, Adam; Remeš, Zdeněk
2017 - English
ZnO is an attractive wide band gap semiconductor with large exciton binding energy, high refractive index, high biocompatibility and diversety of nanostructure shapes which makes it suitable for many applications in the optoelectronic devices, optical sensors, and biosensors. We study the effect of hydrogen plasma treatment of the nominally undoped ZnO thin film deposited by DC reactive magnetron sputtering of Zn target in the gas mixture of argon and oxygen plasma. The SEM images show that the crystal size increases with film thickness. We confirm, that the electrical conductivity significantly increases after hydrogen plasma treatment by 4 orders of magnitude. Moreover, the increase of the infrared optical absorption, related to free carrier concentration, was detected below the optical absorption edge by the photothermal deflection spectroscopy.\n Keywords: ZnO; reactive magnetron sputtering; hydrogen plasma treatment Available at various institutes of the ASCR
Hydrogen plasma treatment of ZnO thin films

ZnO is an attractive wide band gap semiconductor with large exciton binding energy, high refractive index, high biocompatibility and diversety of nanostructure shapes which makes it suitable for many ...

Chang, Yu-Ying; Neykova, Neda; Stuchlík, Jiří; Purkrt, Adam; Remeš, Zdeněk
Fyzikální ústav, 2017

Preparation of zinc oxide nanorods colloid from thin layers
Mičová, Júlia; Remeš, Zdeněk; Chang, Yu-Ying; Neykova, Neda
2017 - English
The interest in ZnO (zinc oxide) nanoparticles is increasing due to low cost of their processing as well as the ability of fabricating ZnO nanostructures with controllable morphology such as size, shape and orientation. Our choice of method of the preparation of the nanostructured thin ZnO layers is the hydrothermal growth of ZnO nanorods on glass substrates coated by the nucleation layer deposited by the reactive magnetron sputtering. We have developed and optimized conditions of the thin layer growth with controllable dimensions of nanorods followed by the ultrasound peeling. The colloid of ZnO nanorods was characterized by measuring the size of particles using the dynamic light scattering (DLS) and the scanning electron microscopy (SEM). We found that the dynamic light scattering (DLS) can’t be directly used for size evaluation of ZnO nanorods due to their non- sperical shape. \n Keywords: ZnO; method hydrothermal growth; thin layer; nanorods Available at various institutes of the ASCR
Preparation of zinc oxide nanorods colloid from thin layers

The interest in ZnO (zinc oxide) nanoparticles is increasing due to low cost of their processing as well as the ability of fabricating ZnO nanostructures with controllable morphology such as size, ...

Mičová, Júlia; Remeš, Zdeněk; Chang, Yu-Ying; Neykova, Neda
Fyzikální ústav, 2017

DLC/TI thin films properties prepared by hybrid laser technologies
Mikšovský, Jan; Jelínek, Miroslav; Písařík, Petr; Kocourek, Tomáš; Remsa, J.; Jurek, Karel
2017 - English
Layers of diamond-like carbon are usable in many fields of industry as well as in medicine. Many scientific groups have worked with different types of deposition techniques to prepare DLC layers with improved or unique properties. The DLC properties could be improved by various dopations. In this study, we focused on DLC layers doped by titanium, prepared by hybrid laser depositions. Two techniques were used: Dual pulse laser deposition (DualPLD) and pulse laser deposition in combination with magnetron sputtering (PLD/MS). Preliminary tests for morphology, wettability, adhesion, hardness, corrosion, friction and wearability were examined. DLC samples were prepared on Si(100) wafer and on Ti6Al4V alloy substrates with titanium concentration from pure up to 25 at.%. Friction of the prepared layers ranged from 0.09 to 0.18. The films exhibited very low wear for loads 1 N and 2 N.\n Keywords: DLC Friction; titanium doped; hybrid deposition Available at various institutes of the ASCR
DLC/TI thin films properties prepared by hybrid laser technologies

Layers of diamond-like carbon are usable in many fields of industry as well as in medicine. Many scientific groups have worked with different types of deposition techniques to prepare DLC layers with ...

Mikšovský, Jan; Jelínek, Miroslav; Písařík, Petr; Kocourek, Tomáš; Remsa, J.; Jurek, Karel
Fyzikální ústav, 2017

The deposition of germanium nanoparticles on hydrogenated amorphous silicon
Stuchlík, Jiří; Volodin, V.A.; Shklyaev, A.A.; Stuchlíková, The-Ha; Ledinský, Martin; Čermák, Jan; Kupčík, Jaroslav; Fajgar, Radek; Mortet, Vincent; More Chevalier, Joris; Ashcheulov, Petr; Purkrt, Adam; Remeš, Zdeněk
2017 - English
We reveal the mechanism of Ge nanoparticles (NPs) formation on the surface of the hydrogenated amorphous silicon (a-Si:H) deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) on ITO and a on boron doped nanocrystalline diamond (BDD). The coating of Ge NPs on a-Si:H was performed by molecular beam epitaxy (MBE) at temperatures up to 450 °C. The Ge NPs were characterized by Raman spectroscopy, scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The nanocrystalline Ge particles are conglomerates of nanocrystals of size 10-15 nm and quantum dots (QDs) with size below 2 nm embedded in amorphous Ge phase. After coating with Ge NPs the a-Si:H thin films show better adhesion on BDD substrates then on ITO substrates. Keywords: Ge nanoparticles; a-Si:H; PECVD; MBE Available at various institutes of the ASCR
The deposition of germanium nanoparticles on hydrogenated amorphous silicon

We reveal the mechanism of Ge nanoparticles (NPs) formation on the surface of the hydrogenated amorphous silicon (a-Si:H) deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) on ITO and a on ...

Stuchlík, Jiří; Volodin, V.A.; Shklyaev, A.A.; Stuchlíková, The-Ha; Ledinský, Martin; Čermák, Jan; Kupčík, Jaroslav; Fajgar, Radek; Mortet, Vincent; More Chevalier, Joris; Ashcheulov, Petr; Purkrt, Adam; Remeš, Zdeněk
Fyzikální ústav, 2017

Spatially separated HOMO/LUMO at interface of polypyrrole physisorbed on oxidized nanodiamond facets
Matunová, Petra; Jirásek, Vít; Rezek, Bohuslav
2017 - English
Nanodiamond particles (NDs) have recently risen in popularity owing to their unique and perspective properties. Merging NDs with organic molecules, such as polypyrrole (PPy), into hybrid organic-semiconductor functional systems gives rise to potential applications in photovoltaics (PV), which is supported by prior experimentally observed charge transfer between bulk diamond and PPy. This work focuses on the most relevant (111) and (100) O-terminated ND facets with different coverage of surface terminating oxygens in ether, epoxide, ketone, and peroxide positions. We use density functional theory (DFT) computations employing B3LYP functional and 6-31G(d) basis set. Energetically the most favorable oxidized ND facets were further optimized with PPy in physisorbed configurations. Analysis of geometry, binding energy, HOMO-LUMO gap, and charge transfer was done on the relaxed PPy-ND structures. Multiple hydrogen bonds are formed between PPy amino groups and O atoms on ND surface. Keywords: diamond; naoparticules; polypyrrole; density functional theory; charge transfer Available at various institutes of the ASCR
Spatially separated HOMO/LUMO at interface of polypyrrole physisorbed on oxidized nanodiamond facets

Nanodiamond particles (NDs) have recently risen in popularity owing to their unique and perspective properties. Merging NDs with organic molecules, such as polypyrrole (PPy), into hybrid ...

Matunová, Petra; Jirásek, Vít; Rezek, Bohuslav
Fyzikální ústav, 2017

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