STRESS-INDUCED EFFECTS IN EPITAXIAL (LA0.7SR0.3)MNO3 FILMS

The transport and magnetic properties of epitaxial (La0.7Sr0.3)MnO3 (L SMO) films deposited on LaAlO3 (Sample L, under a compressive stress) and SrTiO3 (Sample S, under a tensile stress) are compared. The magnet ic force microscope image of Sample L shows a 'maze-like' pattern indi cating a sizable out-of-plane magnetization, while the magnetic image of Sample S shows a 'feather-like' pattern indicative of in-plane magn etization. The hysteresis loop and ferromagnetic resonance measurement s indicate that the lattice mismatch between the film and the substrat e is the origin of the differences in the magnetic anisotropy of the t wo films. Sample L has a smaller 'peak' resistivity and a larger satur ation magnetization at room temperature than Sample S, Our results can be understood by the internal 'pressure' consequent upon lattice mism atch and agree qualitatively with the recent hydrostatic pressure stud ies on the doped manganites.