STRAIN-INDUCED RENORMALIZATION OF TRANSPORT-PROPERTIES IN UPT3 THIN-FILMS

The growth of sputter deposited UPt3 thin films on Al2O3 (10 (1) over bar 2), LaAlO3 (111) and SrTiO3 (111) investigated. We found strongly 0001-textured growth of UPt3 in a small compositional range of 23 - 25 % uranium content. For Al2O3- and LaAlO3-substrates no in-plane order could be observed whereas epitaxial growth was initiated on SrTiO3 (11 1). The growth can be identified as Vollmer-Weber like resulting in th e formation of large lateral strain as a consequence of the growth mod e and a lattice misfit of -4.3% between UPt3 (0001) and SrTiO3 (111). Strong deviations from the typical heavy-fermion characteristics in el ectronic transport properties like resistivity, magnetoresistivity and Hall-effect are attributed to changes of the hybridization between th e localized 5f- and itinerant states.