Zobrazeno 1 - 10
of 2 712
pro vyhledávání: '"D. H. Lowndes"'
Autor:
Lesley F. Cohen, John Gallop, Ling Hao, Hong-Ying Zhai, Mariappan Parans Paranthaman, A. Purnell, D. H. Lowndes, Hans M. Christen
Publikováno v:
Superconductor Science and Technology. 17:681-684
MgB2 is a two-gap superconductor and as a result may manifest unusual physical properties. The performance of MgB2 films at microwave frequencies has so far been rather poor compared to that of Nb alloys and this may result from intrinsic behaviour r
Autor:
Hans M. Christen, Srivatsan Sathyamurthy, Christopher M. Rouleau, D. H. Lowndes, David Mandrus, Hong-Ying Zhai, Peter G. Khalifah, Isao Ohkubo
Publikováno v:
Applied Surface Science. 223:35-38
We have designed an improved pulsed-laser deposition–continuous composition-spread (PLD–CCS) system that overcomes the difficulties associated with earlier related techniques. Our new PLD–CCS system is based on a precisely controlled synchroniz
Autor:
Timothy E. McKnight, D. H. Lowndes, Anatoli V. Melechko, Albina Y. Borisevich, Michael L. Simpson, Michael A. Guillorn, Dale K. Hensley, V. I. Merkulov
Publikováno v:
Nanotechnology. 14:1029-1035
We report on techniques for catalytic synthesis of rigid, high-aspect-ratio, vertically aligned carbon nanofibres by dc plasma enhanced chemical vapour deposition that are tailored for applications that require arrays of individual fibres that featur
Growth behavior of carbon nanotubes on multilayered metal catalyst film in chemical vapor deposition
Autor:
D. H. Lowndes, Maria Varela, David B. Geohegan, Jane Y. Howe, A. A. Puretkzy, Gyula Eres, H. Cui
Publikováno v:
Chemical Physics Letters. 374:222-228
The temperature and time dependences of carbon nanotube (CNT) growth by chemical vapor deposition are studied using a multilayered Al/Fe/Mo catalyst on silicon substrates. Within the 600–1100 °C temperature range of these studies, narrower tempera
Autor:
Hong-Ying Zhai, Ling Hao, Moon-Ho Jo, T Nurgaliev, Mariappan Parans Paranthaman, D. H. Lowndes, Y. Bugoslavsky, G. Lamura, Zainovia Lockman, John Gallop, Judith L. MacManus-Driscoll, Lesley F. Cohen, Mark G. Blamire, A. Purnell, Hans M. Christen, A.A. Zhukov
Publikováno v:
Superconductor Science and Technology. 16:1-6
In this paper we present the results of measurements of the microwave surface impedance of a powder sample and two films of MgB2. The powder sample has a Tc = 39 K and the films have Tc = 29 K and 38 K. These samples show different temperature depend
Autor:
D. H. Lowndes, Mark G. Blamire, Judith L. MacManus-Driscoll, J. D. Moore, Yu.V. Bugoslavsky, Zainovia Lockman, Moon-Ho Jo, A. Berenov, Mariappan Parans Paranthaman, T.J. Tate, Lesley F. Cohen, Hans M. Christen, A D Caplin, L. Cowey, G. K. Perkins, Hong-Ying Zhai
Publikováno v:
Superconductor Science and Technology. 15:1392-1397
We discuss pinning properties of MgB2 thin films grown by pulsed-laser deposition (PLD) and by electron-beam (EB) evaporation. Two mechanisms are identified that contribute most effectively to the pinning of vortices in randomly oriented films. The E
Autor:
D. H. Lowndes, Vladimir I. Merkulov, Michael A. Guillorn, Michael L. Simpson, Anatoli V. Melechko
Publikováno v:
Chemical Physics Letters. 361:492-498
Vertically aligned carbon nanofibers (VACNFs) were synthesized by direct-current plasma enhanced chemical vapor deposition using acetylene and ammonia as the gas source. The mechanisms responsible for changing the nanofiber growth rate were studied a
Autor:
J. H. Whealton, Anatoli V. Melechko, V. I. Merkulov, D. H. Lowndes, Larry R. Baylor, E. D. Ellis, Michael L. Simpson, Michael A. Guillorn
Publikováno v:
Journal of Applied Physics. 91:4602-4606
Field emission from isolated individual vertically aligned carbon nanocones (VACNCs) has been measured using a small-diameter moveable probe. The probe was scanned parallel to the sample plane to locate the VACNCs, and perpendicular to the sample pla
Autor:
Michael L. Simpson, D. H. Lowndes, Anatoli V. Melechko, Phillip F. Britt, V. I. Merkulov, Timothy E. McKnight, Michael A. Guillorn, Derek W. Austin
Publikováno v:
Journal of Applied Physics. 91:3824-3828
In this paper we present the fabrication and initial testing results of high aspect ratio vertically aligned carbon nanofiber (VACNF)-based electrochemical probes. Electron beam lithography was used to define the catalytic growth sites of the VACNFs.
Autor:
Claudia Cantoni, D. H. Lowndes, Hong-Ying Zhai, Brian C. Sales, David K. Christen, P H Fleming, L. Zhang, Hans M. Christen, Mariappan Parans Paranthaman
Publikováno v:
Scopus-Elsevier
The growth mechanisms of MgB2 films obtained by different methods on various substrates are compared via a detailed cross-sectional scanning electron microscopy (SEM) study. The analyzed films include (a) samples obtained by an ex-situ post-anneal at