Browsing by Subject "Silica"

Article

Controlled production of ZnO nanoparticles from zinc glycerolate in a sol-gel silica matrix

Moleski, R.; Leontidis, Epameinondas; Krumeich, F. (2006)

The controlled production of ZnO nanoparticles within an amorphous silica matrix is achieved using a new methodology consisting of four stages. First, precursor zinc glycerolate nanoparticles are produced within reversed ...

Conference Object

Femtosecond laser inscription of Bragg and complex gratings in coated and encapsulated silica and low-loss polymer optical fibers

Kalli, Kyriacos; Lacraz, A.; Polis, M.; Othonos, Andreas S. (SPIE, 2015)

The development of wavelength filters, such as Bragg and superstructure gratings in glass and polymer optical fibers, using a femtosecond laser is reported. By using a femtosecond laser operating in the green, which offers ...

Article

Hydrogen production by ethylene decomposition over Ni supported on novel carbon nanotubes and nanofibers

Savva, Petros G.; Olympiou, G. G.; Costa, Costas N.; Ryzhkov, V. A.; Efstathiou, Angelos M. (2005)

Ethylene decomposition over Ni supported on novel carbon nanotubes (CNT) and nanofibers under consecutive reaction/regeneration cycles to form CO-free hydrogen and carbon deposits have been investigated. The present work ...

Article

Optical response of thin supported palladium films to hydrogen: Non-destructive testing for hydrogen detection

Christofides, Constantinos; Kalli, Kyriacos; Othonos, Andreas S. (1999)

The properties of thin palladium films on silicon dioxide/silicon substrates are investigated. As the electrical properties of very thin palladium films cannot be measured, due to highly discontinuous nature of the films ...

Article

Organized silica films generated by evaporation-induced self-assembly as hosts for iron oxide nanoparticles

Andreou, Ioanna; Amenitsch, H.; Likodimos, Vlassis; Falaras, Polycarpos; Koutsoukos, Petros George; Leontidis, Epameinondas (2013)

In this work, we prepared oriented mesoporous thin films of silica on various solid substrates using the pluronic block copolymer P123 as a template. We attempted to insert guest iron oxide (FexOy) nanoparticles into these ...

Article

Quantum confinement and interface structure of Si nanocrystals of sizes 3-5 nm embedded in a-SiO2

Lioudakis, Emmanouil E.; Othonos, Andreas S.; Hadjisavvas, G. C.; Kelires, P. C.; Nassiopoulou, Androula Galiouna (2007)

Spectroscopic ellipsometry and Monte Carlo simulations are employed to answer the fundamental question whether the energy gaps of Si nanocrystals with sizes in the range of 3-5 nm, which are embedded in amorphous silica, ...

Article

Superimposed gratings WDM on Ge-doped silica on silicon planar waveguide

Bismuth, J.; Othonos, Andreas S.; Sweeny, M.; Kevorkian, A.; Xu, J. M. (1996)

Wavelength-division multiplexed (WDM) devices are becoming increasingly important for fiber-optics communication and sensing systems. Large-channel fanout, low loss, and compatibility with fiber connection, laser sources ...

Article

Temperature programmed reduction of silica supported nickel catalysts

Afzal, M.; Theocharis, Charis R.; Karim, S. (1993)

Nickel oxide promoted catalysts are prepared by simple precipitation, precipitation from homogeneous solution and impregnation methods and their reduction behavior is monitored with temperature programmed reduction (TPR) ...

Article

Thermoelectric properties of Bi0.5Sb1.5Te3 thin films grown by pulsed laser deposition

Symeou, E.; Pervolaraki, M.; Mihailescu, C. N.; Athanasopoulos, G. I.; Papageorgiou, C.; Kyratsi, Theodora; Giapintzakis, John (2015)

We report on the pulsed laser deposition of p-type Bi0.5Sb1.5Te3 thin films onto fused silica substrates by ablation of dense targets of Bi0.5Sb1.5Te3 with an excess of 1 wt% Te. We investigated the effect of film thickness, ...

Article

Transient isotopic kinetic study of the NO/H2/O2 (lean de-NOx) reaction on Pt/SiO2 and Pt/La-Ce-Mn-O catalysts

Costa, Costas N.; Efstathiou, Angelos M. (2004)

Steady-state isotopic transient kinetic analysis (SSITKA) coupled with temperature-programmed surface reaction (TPSR) methods and using in situ mass spectroscopy and DRIFTS have been applied for the first time to study ...