In situ preparation of RENi2B2C (RE – Y, Ho) thin films by pulsed laser deposition

Thin films of RENi2B2C (RE - Y, Ho) have been prepared in situ by pulsed laser deposition on MgO(100) substrates with and without tungsten buffer layers. We find that the formation of impurity phases is strongly dependent on the substrate used, indicating a substrate-film reaction. The films are polycrystalline and mainly c-axis oriented. The YNi2B2C films show sharp superconducting transitions up to 14.7 K with a transition width of 0.3 K. With the HoNi2B2C films, superconductivity was found at 8.5 K with a transition width of 0.5 K. In YNi2B2C films we find a higher anisotropy of B-c2(T) than for single crystals, while the HoNi2B2C films show the same behavior as single crystals. (C) 2000 Elsevier Science B.V. All rights reserved.