Growth characteristics of sputter-deposited UPt sub 3 thin films

• Published in: Journal of physics. Condensed matter Vol. 8; no. 45; pp. 8777 - 8786
• Main Authors: Huth, M, Reber, S, Heske, C, Schickatanz, P, Hessert, J, Gegenwart, P, Adrian, H
• Format: Journal Article
• Language: English
• Published: 04.11.1996
• ISSN: 0953-8984

Thin films of the heavy-fermion superconductor UPt sub 3 were deposited on various substrate materials in various orientations by means of a quasi-multilayer sputter process. Strongly (0001)-textured growth of the hexagonal compound was found for a uranium content in the range of 23% to 28% on sapphire (1012), LaAlO sub 3 (111) and SrTiO sub 3 (111) with perfect in-plane order on the latter substrate material. Atomic force microscopy and scanning electron microscopy revealed a Vollmer-Weber-like growth mode resulting in the development of large compressive strain in films on SrTiO sub 3 (111). As a result the electronic transport properties--in particular the temperature dependence of the resistivity--were strongly renormalized. Strong deviations from the typical heavy-fermion characteristics known from UPt sub 3 bulk samples were found in films on SrTiO sub 3 with residual resistance ratios pi (300K)/ pi sub 0 up to 930 and a significantly reduced superconducting transition temperature of 130mK.