National Repository of Grey Literature 6 records found  Search took 0.01 seconds. 
Fabrication of 3D diamond membranes for microfluidic systems
Varga, Marián ; Babchenko, Oleg ; Bauerová, Pavla ; Hruška, Karel ; Jurka, Vlastimil ; Kromka, Alexander ; Rezek, Bohuslav
Perfusion of cell medium, especially in microfluidic devices, can provide in-vivo-like conditions for cell cultures. The most recent demand on such systems is to include electronically active artificial cell support for in-situ monitoring. Diamond thin films exhibit advantageous combination of physical, mechanical, chemical, biocompatible and electronic properties for this purpose. In this work we explore two strategies for fabrication of self-standing three-dimensional nanocrystalline diamond membrane for implementation in microfluidic invivo like experiments: i) nucleation and chemical vapour deposition (CVD) growth of diamond on porous 3D carbon foam (with 80 pores per inch) and ii) selective diamond growth predefined by photolithographic processing using copper grid mask. The morphology and material quality of the fabricated membranes are characterized by scanning electron microscopy and Raman spectroscopy.
Growth of diamond thin films: a review
Kromka, Alexander ; Potocký, Štěpán ; Rezek, Bohuslav
Diamond is shown as an extraordinary material which offers promising solution for variety of fundamental studies and industrial uses. Here, growth of synthetic diamond films at low pressures (1 atm) and low temperatures (<1000°C) from carbon consisting gas mixtures is discussed. Variety of chemical vapor deposition techniques are reviewed, their advantages and disadvantages are pointed out too.
Foreign substrates pre-treatment using polymer composites in plasma-enhanced CVD growth of diamond fibers and layers
Potocký, Štěpán ; Babchenko, Oleg ; Ižák, Tibor ; Varga, Marián ; Kromka, Alexander ; Rezek, Bohuslav ; Tesárek, P.
Nanocrystalline diamond wires and layers were grown by microwave plasma CVD technique on Si substrates. The substrates were pretreated by non-woven composite nanofiber textile composed by poly(vinyl alcohol) matrix and ultra-dispersed diamond (UDD) nanoparticles prepared by needleless electrospinning method. High concentration of UDD in the PVA fibers lead to formation of diamond wires due to a combined effect of UDD particles used as seeding and high pressure difference across the fibers interface. A preferable growth of diamond layers was observed on areas with a low porosity volume of nanofiber textile. The influence of spundond structure on the growth of diamond decreased with lowering of UDD concentra-tion in the primary polymer matrix.
Diamond chemical vapor deposition
Kromka, Alexander
Present paper reviews growth of diamond thin films by various chemical vapor deposition processes. Basic characteristics and common features of processes are pointed out with a respect to quality of grown films and standard process parameters. Novel and non-standard diamond syntheses techniques are briefly discussed.
Pulsed linear antenna microwave plasma – a step ahead in large area material depositions and surface functionalization
Kromka, Alexander ; Babchenko, Oleg ; Ižák, Tibor ; Potocký, Štěpán ; Davydova, Marina ; Neykova, Neda ; Kozak, Halyna ; Remeš, Zdeněk ; Hruška, Karel ; Rezek, Bohuslav
A technological progress in the large area growth of diamond films and carbon nanotubes by the modified linear antenna MW system is presented. We show a correlation between process parameters and nano- or poly-crystalline film character. A challenging part, diamond coated mirrors or ATR prisms, are shown as multifunctional optical elements suitable for detection of absorbed molecules. Additional positive feature of the presented plasma system is low temperature hydrogen functionalization of diamond films. Finally, we present that combination of pulsed MW plasma with radiofrequency substrate biasing results in growth of oriented CNTs over large area.
Použití mikrovlnného plazmatu pro syntézu alfa-Fe nanočástic
Hoder, T. ; Kudrle, V. ; Frgala, Z. ; Janča, J. ; David, Bohumil
Microwave induced plasma decomposition of iron pentacarbonyl has been used to prepare iron nanosized particles. Vapours of iron pantacarbonyl have been introduced into argon surfaguide discharge, optical mission spectra have been taken and rotational and vibrational temperatures obtained. The temperatures were plotted as a functions of axial and radial distance and of iron pentacarbonyl concentration. Iron nanoparticles have been produced, XRD results and TEM images were obtained. The core-shell nanoparticles were observed, with alpha phase iron as a core and Fe(x)O(y)/C shell.

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