Strain effects on the magnetic properties of epitaxial SrRuO$_{3}$ thin films

We study the effects of lattice strain on the magnetic behavior of epitaxial SrRuO$_{3}$ thin films grown by pulsed laser deposition. Most films have been grown on SrTiO$_{3}$ and KTaO$_{3}$ substrates that provide compressive and tensile strain, respectively. The Curie temperature (Tc) is reduced compared to the corresponding bulk for compressively strained SrRuO$_{3}$ films. This is consistent with previous results. Tc is enhanced an almost equal amount for films under tension. The transition temperature shows a fairly large change between the films with different types of strain (compressive and tensile), but further variation of strain produces only small changes in Tc. The rise in Tc with tensile strain is unique as far as we know. We present the temperature-strain phase diagram of SrRuO$_{3}$ thin films and discuss possible mechanisms for the strain dependent changes in magnetic properties. This work is supported through NSF DMR-0239667. Some data was taken at the National Synchrotron Light Source, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Division of Materials Sciences and Division of Chemical Sciences, under Contract No. DE-AC02-98CH10886.