Browsing by Subject "X ray diffraction"

Article

A2Bi8Se13 (A = Rb, Cs), CsBi3.67Se6, and BaBi2Se4: New ternary semiconducting bismuth selenides

Iordanidis, L.; Brazis, P. W.; Kyratsi, Theodora; Ireland, J.; Lane, M.; Kannewurf, C. R.; Chen, W.; Dyck, J. S.; Uher, C.; Ghelani, N. A.; Hogan, T.; Kanatzidis, M. G. (2001)

Rb2Bi8Se13 (I), Cs2Bi8Se13 (II), CsBi3.67Se6 (III), and BaBi2Se4 (IV) were synthesized by direct combination reactions of the A/Se (A = Rb, Cs, Ba) and Bi2Se3 at ≥650 °C. Their structures were determined by single-crystal ...

Article

Adaptive VN/Ag nanocomposite coatings with lubricious behavior from 25 to 1000 °c

Aouadi, S. M.; Singh, D. P.; Stone, D. S.; Polychronopoulou, K.; Nahif, F.; Rebholz, Claus; Muratore, C.; Voevodin, A. A. (2010)

A two-phase nanocomposite coating that consists of inclusions of silver in a vanadium nitride matrix (VN/Ag) was investigated as a potential adaptive coating with a reduced friction coefficient from 25 to 1000 °C. This ...

Article

Broom-like and flower-like heterostructures of silver molybdate through pH controlled self assembly

Singh, D. P.; Sirota, B.; Talpatra, S.; Kohli, P.; Rebholz, Claus; Aouadi, S. M. (2012)

Silver molybdate microrods are selfassembled into micron sized, broom-like and flowerlike structures. Our investigations indicate that through a simple hydrothermal process, large scale production of such structure is ...

Article

Data storage applications based on LiCoO2 thin films grown on Al2O3 and Si substrates

Svoukis, E.; Mihailescu, C. N.; Mai, V. H.; Schneegans, O.; Breza, K.; Lioutas, C.; Giapintzakis, John (2015)

In this study, LiCoO2 thin films were investigated for data storage applications based on scanning probe mediated approaches. LiCoO2, compared to other materials proposed for scanning probe mediated nanoscale patterning, ...

Article

Deposition and nanotribological characterization of Sub-100-nm thick protective Ti-based coatings for miniature applications

Polychronopoulou, K.; Lee, J.; Tsotsos, C.; Demas, N. G.; Meschewski, R. L.; Rebholz, Claus; Polycarpou, A. A. (2011)

Ti-based protective thin films with thicknesses below 100 nm, intended for miniature applications were deposited using physical vapor deposition magnetron sputtering. X-ray diffraction (XRD), scanning electron microscopy, ...

Article

Effect of Bi-doping and Mg-excess on the thermoelectric properties of Mg2Si materials

Ioannou, M.; Polymeris, G. S.; Hatzikraniotis, E.; Paraskevopoulos, K. M.; Kyratsi, Theodora (2014)

In this work, Bi-doped magnesium silicide compounds were prepared by applying a combination of both, short-time ball milling and heating treatment. The effect of Mg excess was also studied, aiming towards further improvement ...

Conference Object

Effect of Cu content on the tribological performance of Cr-N coatings at high temperatures (840°C)

Polychronopoulou, K.; Rebholz, Claus; Demas, N. G.; Polycarpou, A. A.; Gibson, P. N. (Affiliation: Department of Mechanical and Manufacturing Eng., University of Cyprus, Nicosia, CyprusAffiliation: Department of Mechanical Science and Eng., University of Illinois at Urbana-Champaign, Urbana, IL, United StatesAffiliation: Institute for Health and Consumer Protection, Joint Res. Centre of the European Commission, Ispra (VA), ItalyCorrespondence Address: Polychronopoulou, K.Department of Mechanical and Manufacturing Eng., University of Cyprus, Nicosia, Cyprus, 2010)

Cr-N and Cu-Cr-N coatings with Cu content between 3-65 at.%, Cu/Cr ratios in the 0.04-4.5 range and 21-27 at.% N, synthesized by twin e-beam Physical Vapor Deposition (EBPVD) at 450°C, were investigated. Using X-ray ...

Article

Effect of silicon nitride/oxide on the structure and the thermal conductivity of CoSi nanocomposites

Ioannou, M.; Delimitis, A.; Symeou, E.; Giapintzakis, John; Kyratsi, Theodora (2017)

In this work, the fabrication of nanocomposites with silicon nitride/oxide into the thermoelectric matrix of cobalt silicide is presented. The different concentrations of nano-Si3N4 were intentionally introduced by mechanical ...

Article

Enhanced growth and photoluminescence properties of SnxN y (x>y) nanowires grown by halide chemical vapor deposition

Zervos, Matthew; Othonos, A. (2011)

Tin nitride nanowires have been grown by halide chemical vapor deposition via the reaction of Sn with NH4Cl at 425 °C under a steady flow of NH3 using small ramp rates y) with a hexagonal structure, i.e. c=5.193 , a=3.725 ...

Article

Fabrication and characterization of superparamagnetic and thermoresponsive hydrogels based on oleic-acid-coated Fe3O4 nanoparticles, hexa(ethylene glycol) methyl ether methacrylate and 2-(acetoacetoxy)ethyl methacrylate

Papaphilippou, P.; Pourgouris, A.; Marinica, O.; Taculescu, A.; Athanasopoulos, G. I.; Vekas, L.; Krasia-Christoforou, T. (2011)

Stimuli-responsive hydrogel nanocomposites comprised of swollen polymer networks, in which magnetic nanoparticles are embedded, are a relatively new class of "smart" soft materials presenting a significant impact on various ...

Article

Fabrication of nanocrystalline Mg 2Si via ball milling process: Structural studies

Ioannou, M.; Hatzikraniotis, E.; Lioutas, C.; Hassapis, T.; Altantzis, T.; Paraskevopoulos, K. M.; Kyratsi, Theodora (2012)

In this work, nanocrystalline Mg 2Si material was fabricated via wet ball milling process using n-hexane as process control agent. Milling parameters, with emphasis on milling time and ball size, and conditions were studied ...

Article

Fabrication, characterization and applications of novel nanoheater structures

Gu, Z.; Cui, Q.; Chen, J.; Buckley, J.; Ando, T.; Erdeniz, D.; Wong, P.; Hadjiafxenti, A.; Epaminonda, P.; Gunduz, I. E.; Rebholz, Claus; Doumanidis, C. C. (2013)

Nanoheaters are reactive nanostructures that can generate localized heat through controlled ignition. Besides the widely used nanofoil structure with multiple alternative Al-Ni layers, various new nanostructures have been ...

Article

Few-layer graphene-like flakes derived by plasma treatment: A potential material for hydrogen adsorption and storage

Kostoglou, N.; Tarat, A.; Walters, I.; Ryzhkov, V.; Tampaxis, C.; Charalambopoulou, Georgia; Steriotis, T.; Mitterer, C.; Rebholz, Claus (2016)

A novel, one-step, wet-free, environmental friendly and high-yield method for producing few-layer graphene powders with large surface areas (up to 800 m2/g) and narrow nanopore sizes (0.7-0.8 nm) using plasma-induced ...

Article

Few-step synthesis, thermal purification and structural characterization of porous boron nitride nanoplatelets

Kostoglou, N.; Lukovic, J.; Babic, B.; Matovic, B.; Photiou, D.; Constantinides, G.; Polychronopoulou, K.; Ryzhkov, V.; Grossmann, B.; Mitterer, C.; Rebholz, Claus (2016)

Hexagonal boron nitride (h-BN) nanoplatelets with 99 wt.% purity, 900 to 2000 nm particle width, 30 to 90 nm particle thickness, 213 m2/g specific surface area (SSA), 66% micropore SSA and 0.85 nm average pore size were ...

Article

Growth and structural characterization of orthorhombic and tetragonal SrCuO2 thin films

Mihailescu, C. N.; Pasuk, I.; Athanasopoulos, G. I.; Luculescu, C.; Socol, M.; Saint-Martin, R.; Revcolevschi, A.; Giapintzakis, John (2013)

Epitaxial SrCuO2 thin films were grown on (0 0 1) SrTiO 3 substrates by pulsed laser deposition using a stoichiometric target. X-ray diffraction indicated that the SrCuO2 films undergo a structural phase transition as a ...

Article

High yield-low temperature growth of indium sulphide nanowires via chemical vapor deposition

Zervos, Matthew; Papageorgiou, P.; Othonos, A. (2010)

Indium sulphide nanowires (NWs) have been grown on Si via the reaction of In and InCl3 with H2S using chemical vapor deposition at temperatures as low as 250 °C. We find that the growth of InxSy NWs via the direct reaction ...

Article

An investigation into the conversion of In2O3 into InN nanowires

Papageorgiou, P.; Zervos, Matthew; Othonos, A. (2011)

Straight In2O3 nanowires (NWs) with diameters of 50 nm and lengths ≥2 μm have been grown on Si(001) via the wet oxidation of In at 850°C using Au as a catalyst. These exhibited clear peaks in the X-ray diffraction corresponding ...

Article

LaSrMnCoO6: A new cubic double perovskite oxide

Androulakis, J.; Katsarakis, N.; Giapintzakis, John; Vouroutzis, N.; Pavlidou, E.; Chrissafis, K.; Polychroniadis, E. K.; Perdikatsis, V. (2003)

Single-phase polycrystalline powder samples of the double perovskite oxide LaSrMnCoO6 were synthesized by the Pechini (citrate-gel) technique. The structural, magnetic and electrical properties of the obtained powders were ...

Article

Magnetic properties of Fe3O4 thin films grown on different substrates by laser ablation

Paramês, M. L.; Viskadourakis, Z.; Rogalski, M. S.; Mariano, J.; Popovici, N.; Giapintzakis, John; Conde, O. (2007)

Magnetite thin films have been grown onto (1 0 0)Si, (1 0 0)GaAs and (0 0 0 1)Al2O3, at substrate temperatures varying from 473 to 673 K, by UV pulsed laser ablation of Fe3O4 targets in reactive atmospheres of O2 and Ar, ...

Article

Microstructure and nanomechanical properties of pulsed excimer laser deposited DLC:Ag films: Enhanced nanotribological response

Constantinou, M.; Pervolaraki, M.; Nikolaou, P.; Prouskas, C.; Patsalas, P.; Kelires, P.; Giapintzakis, John; Constantinides, G. (2017)

Diamond-like carbon:silver (DLC:Ag) thin films, with metal contents as high as 16.8 at.%, have been deposited on silicon substrates using pulsed excimer laser deposition