• Article  

      Anisotropy of the resistivity in the a-b plane of a superconducting YBa2Cu3O7-δ single crystal 

      Kim, J.-T.; Giapintzakis, John; Ginsberg, D. M. (1996)
      We have measured the in-plane longitudinal resistivities pa and pb as functions of temperature and magnetic field. The measurements were all made on the same detwinned single crystal of YBa2Cu3O7-δ (YBCO). Defining Tc to ...
    • Article  

      Correlation of elastic modulus, hardness and density for sputtered TiAlBN thin films 

      Rebholz, Claus; Leyland, A.; Matthews, A.; Charitidis, C.; Logothetidis, S.; Schneider, D. (2006)
      This paper describes the correlation between the elastic modulus, hardness and density of mainly X-ray amorphous TiAlxByNz (0.29 ≤ x ≤ 1.32
    • Article  

      Disorder-induced vortex phase transition in untwinned YBa2Cu3O7-δ crystal 

      Giller, D.; Giapintzakis, John; Shaulov, A.; Yeshurun, Y. (2000)
      Local magnetic measurements in an untwinned YBa2Cu3O7-δ crystal as a function of temperature, field and time reveal anomalies occurring along the same line BSS(T) in the field-temperature plane. We identify BSS(T) as a ...
    • Conference Object  

      Doping and alloying trends in new thermoelectric materials 

      Loo, S.; Lal, S.; Kyratsi, Theodora; Chung, D. Y.; Hsu, K. F.; Kanatzidis, M. G.; Hogan, T. P. (Affiliation: Dept. of Elec. and Comp. Engineering, Michigan State University, East Lansing, MI, United StatesCorrespondence Address: Loo, S.Dept. of Elec. and Comp. Engineering, Michigan State University, East Lansing, MI, United States, 2002)
      New thermoelectric bulk materials such as CsBi4Te6 have shown superior properties to traditional materials, however, optimal performance requires continuing investigations of doping and alloying trends. A recently modified ...
    • Conference Object  

      Doping studies of n-type CsBi4Te6 thermoelectric materials 

      Lane, M. A.; Ireland, J. R.; Brazis, P. W.; Kyratsi, Theodora; Chung, D. Y.; Kanatzidis, M. G.; Kannewurf, C. R. (Affiliation: Dept of Electrical and Computer Eng., Northwestern University, Evanston, IL 60208, United StatesCorrespondence Address: Lane, M.A.Dept of Electrical and Computer Eng., Northwestern University, Evanston, IL 60208, United States, 2001)
      We have previously reported the successful p-type doping of CsBi4Te6 which had a high figure of merit at temperatures below 300 K. In this study, several dopants were explored to make n-type CsBi4Te6. A program of measurements ...
    • Article  

      The effect of Fe on the catalytic behavior of model Pd-Rh/CeO2-Al2O3 three-way catalyst 

      Lambrou, Panayiota S.; Savva, Petros G.; Fierro, José Luis García; Efstathiou, Angelos M. (2007)
      The present work attempts to address the issue whether iron (Fe) which is accumulated on the surface of "three-way" catalysts (TWCs) used in gasoline-driven cars is a true chemical poison of their catalytic activity. This ...
    • Article  

      Ellipsometric analysis of ion-implanted polycrystalline silicon films before and after annealing 

      Lioudakis, Emmanouil E.; Nassiopoulou, Androula Galiouna; Othonos, Andreas S. (2006)
      A study of arsenic ion-implanted polycrystalline silicon films before and after annealing at various temperatures has been performed using spectroscopic ellipsometry in the ultraviolet to the visible spectral region. Using ...
    • Article  

      Hall effect in detwinned single crystals of YBa2(Cu1-xZnx)3O7-δ in the mixed state 

      Schegolev, A. I.; Giapintzakis, John; Manson, J. T.; Ginsberg, D. M.; Dumler, I. (1996)
      The effect of zinc doping on the mixed-state Hall effect in detwinned single crystals of YBa2Cu3O7-δ has been studied. We observe a sign reveral of the Hall effect in crystals with a superconducting transition temperature ...
    • Conference Object  

      Initial assessment of the thermoelectric properties for the mixed system K2-xRbxBi8Se13 

      Ireland, J. R.; Kyratsi, Theodora; Kanatzidis, M. G.; Kannewurf, C. R. (Affiliation: Dept. of Elec. and Comp. Engineering, Northwestern University, Evanston, IL 60208-3118, United StatesCorrespondence Address: Ireland, J.R.Dept. of Elec. and Comp. Engineering, Northwestern University, Evanston, IL 60208-3118, United States, 2002)
      In previous studies we have investigated the thermoelectric properties of undoped and doped compositions of β-K2Bi8Se13. The attempt to substitute Rb for K resulted in a different structure type, but with potentially useful ...
    • Article  

      Large positive magnetoresistance in nonstoichiometric NiMnSb thin films on silicon 

      Branford, W. R.; Clowes, S. K.; Syed, M. H.; Bugoslavsky, Y. V.; Gardelis, S.; Androulakis, J.; Giapintzakis, John; Grigorescu, C. E. A.; Berenov, A. V.; Roy, S. B.; Cohen, L. F. (2004)
      The transport properties of pulsed-laser-deposited NiMnSb films on silicon as a function of film thickness were discussed. It was found that a low-temperature upturn was observed in the resistivity for film thicknesses of ...
    • 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  

      Normal and defective perylene substitution sites in alkane crystals 

      Leontidis, Epameinondas; Heinz, H.; Palewska, K.; Wallenborn, E. -U; Suter, U. W. (2001)
      The substitution nature of perylene in polycrystalline solid alkane matrices was examined. Low temperature excitation-emission matrix spectroscopy was used to determine substitution sites in alkane matrices from hexane to ...
    • 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  

      Photothermal measurements of differential reflectivity of YBCO related to the symmetry of the superconducting order parameter 

      Fishman, I. M.; Studenmund, W. R.; Kino, G. S.; Giapintzakis, John (1996)
      We have investigated symmetry of the differential optical response of single YBCO domains in the a-b plane. As a function of temperature, this response consists of a smooth background and a sharp peak in the vicinity of ...
    • Article  

      Probing the environment of CuB in heme-copper oxidases 

      Daskalakis, Vangelis; Pinakoulaki, Eftychia; Stavrakis, Stavros; Varotsis, Constantinos (2007)
      Time-resolved step-scan FTIR (TRS2-FTIR) and density functional theory have been applied to probe the structural dynamics of CuB in heme-copper oxidases at room temperature. The TRS2-FTIR data of cbb3 from Pseudomonas ...
    • Article  

      Progress in photothermal microscopy of YBa2Cu3O7-x 

      Studenmund, W. R.; Fishman, I. M.; Kino, G. S.; Giapintzakis, John (1998)
      We present recent differential optical reflectivity (DOR) measurements obtained at 633 nm (2.OeV), 780 nm (1.6eV), 1064 nm (1.16eV), and 1310nm (0.95 eV). We discuss calibration techniques which can correct for variations ...
    • Article  

      Pulsed-laser deposition of NiMnSb thin films at moderate temperatures 

      Giapintzakis, John; Grigorescu, C.; Klini, A.; Manousaki, A.; Zorba, V.; Androulakis, J.; Viskadourakis, Z.; Fotakis, C. (2002)
      Thin films of the half-Heusler alloy NiMnSb, which is predicted by band-structure calculations to be a half-metallic ferromagnet, were grown on various substrates (Si and InAs) using pulsed-laser deposition. The growth ...
    • Article  

      Rates of activation and scanning electron microscopy of polyarylamide-derived chars 

      Tomlinson, J. B.; Freeman, J. J.; Sing, K. S. W.; Theocharis, Charis R. (1995)
      Fibrous activated carbons were prepared from Kevlar® (poly (p-phenylene terephthalamide)) and Nomex® (poly (m-phenylene isophthalamide)) by carbonisation in nitrogen and subsequent activation in steam of carbon dioxide to ...
    • Article  

      Reactions of 1,2,3-dithiazoles with halogenated malononitriles 

      Christoforou, Irene C.; Koutentis, Panayiotis Andreas; Rees, C. W. (2002)
      Dibromomalononitrile 3a reacts with 4-chloro-1,2,3-dithiazole-5-thione 9 and monobromomalononitrile 3c reacts with 4,5-dichloro-1,2,3-dithiazolium chloride 4 (Appel salt) to give 4-chloro-5H-1,2,3-dithiazole-5-ylidenemalononitrile ...
    • Article  

      Study of copper sulfide crystallization in PEO-SDS solutions 

      Orphanou, M.; Leontidis, Epameinondas; Kyprianidou-Leodidou, Tasoula; Koutsoukos, Petros George; Kyriacou, Kyriacos C. (2004)
      The crystallization of copper sulfide in aqueous supersaturated solutions in the presence of the polymer poly(ethylene oxide), PEO, and the surfactant sodium dodecyl sulfate, SDS, was investigated. In these systems, copper ...