Dresden 2009 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 18: Superconductivity: Fabrication and Characterization

TT 18.5: Talk

Tuesday, March 24, 2009, 15:15–15:30, HSZ 105

Ion-beam assisted deposition of textured transition metal nitride films — •Martin Kidszun, Ruben Hühne, Bernhard Holzapfel und Ludwig Schultz — IFW Dresden, Institute for Metallic Materials, P.O. Box 270116, D-01171 Dresden, Germany

Ion-beam assisted deposition (IBAD) offers the opportunity to prepare thin textured films on non-textured substrates. A textured nucleation was observed in materials with a rocksalt structure like MgO or TiN under appropriate deposition conditions. Therefore, the IBAD approach was used to investigate, if other superconducting transition metal nitrides can be textured in a similar way. The films were prepared on amorphous Si3N4 seed layers in a reactive process using pulsed laser deposition of pure metals in combination with a nitrogen containing ion-beam. The texture development was studied in-situ using reflection high-energy electron diffraction. It was found, that NbN reveals a textured nucleation similar to MgO or TiN. The biaxial texture was stabilised to thicker layers using homoepitaxial growth. Highly textured NbN layers were realised on amorphous substrates with an in-plane alignment below 5°. In dependence of the nitrogen pressure applied during the homoepitaxial growth, superconducting transition temperatures up to 14 K were observed. A clear correlation between structural and superconducting properties was found. Additionally, the oxygen incorporated in the NbN layer has a significant influence on the superconducting properties. Finally, a textured nucleation was also found for the reactive preparation of ZrN using ion-beam assisted laser deposition.