CHARACTERIZATION OF EPITAXIAL LA0.7BA0.3MNO3 STRUCTURES USING FERROMAGNETIC-RESONANCE

We have compared a single layer of La0.7Ba0.3MnO3 and a trilayer struc ture of SrTiO3/La0.7Ba0.3MnO3/SrTiO3, both grown epilaxiaily on a LaAl O3 substrate, using information obtained by ferromagnetic resonance (F MR). The trilayer samples have a more uniform magnetization and are no t susceptible to environmental degradation. This may be due to the str ain relief that the buffer SrTiO3 layer provides for the La0.7Ba0.3MnO 3 layer. We have also studied the magnetic homogeneity of the trilayer structure as a function of the deposition temperature. The perpendicu lar FMR linewidth, Gamma(perpendicular to), shows a clear window in ti le deposition temperature where the linewidth is <50 Oe. However, the parallel linewidth, Gamma(parallel to), is nearly ten times larger tha n Gamma(perpendicular to) with only 3 weak dependence on the depositio n temperature. This broadening of the parallel linewidth compared to t he perpendicular linewidth can be explained by invoking a local unidir ctional anisotropy in the plans of the film. (C) 1996 American Instit ute of Physics.