THE INFLUENCE OF ENERGETIC BOMBARDMENT ON THE STRUCTURE AND PROPERTIES OF EPITAXIAL SRRUO3 THIN-FILMS GROWN BY PULSED-LASER DEPOSITION

SrRuO3 epitaxial thin films were prepared by pulsed laser deposition ( PLD) under a range of growth conditions to study the impact of bombard ment on properties. Growth conditions favoring energetic bombardment r esulted in SrRuO3 films with expanded in-plane and out-of-plane lattic e constants. In particular, SrRuO3 films with pseudocubic out-of-plane lattice constants as large as 4.08 Angstrom were deposited (3.8% larg er than the bulk value). Those films with expanded lattices had greate r resistivities and depressed Curie transition temperatures. The relat ive lattice mismatch between film and substrate was found to temper th e effect of bombardment such that as the mismatch increased, a higher degree of bombardment was required to produce extended lattice paramet ers. The pressure-dependent energetic species inherent to PLD and thei r interaction with the ambient are believed to be the source of the bo mbarding flux. Further experiments confirmed that in the range of 20-2 00 mTorr, oxygen/ozone partial pressure had a negligible effect on the film properties. (C) 1998 American Institute of Physics.