Dresden 2009 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 5: Postersession Superconductivity: Materials - Fabrication and Properties
TT 5.4: Poster
Montag, 23. März 2009, 13:00–16:45, P1A
Superconducting Properties of Niobium Thin Films grown by Pulsed Laser Deposition — Christian Pansow1, •Veit Grosse1, Alexander Steppke2, Frank Schmidl1, and Paul Seidel1 — 1Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena, Helmholtzweg 5, 07743 Jena — 2MPI für chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden
Niobium (Nb) as the element showing the highest critical temperature is the most commonly used material for superconducting applications. High quality thin films can be fabricated utilising electron beam evaporation or sputtering. However, special demands on the device fabrication process may favour other deposition techniques. Note, for example, the possibility for an in situ growth of multilayer systems, the realisation of new Josephson Junction concepts utilising carbon nanotubes or improving film quality by increasing ionisation of the evaporated material. In this framework pulsed laser deposition is a versatile technique to meet these demands.
Here we report on the superconducting properties of niobium thin films grown by pulsed laser deposition at room temperature. Depending on film thickness we achieved a critical temperature of 8.4 K and a critical current density of 3.0·106 A/cm2 at 4.2 K. We compare the temperature dependence of the critical current and critical magnetic field with that of electron evaporated niobium films. Our samples showed a distinct ageing behaviour during several cooling cycles which can be attributed to oxygen diffusion into the fine grained structure of the films.