We have compared a single layer of La0.7Ba0.3MnO3and a trilayer structure of SrTiO3/La0.7Ba0.3MnO3/SrTiO3, both grown epitaxially on a LaAlO3substrate, using information obtained by ferromagnetic resonance (FMR). The trilayer samples have a more uniform magnetization and are not susceptible to environmental degradation. This may be due to the strain relief that the buffer SrTiO3layer provides for the La0.7Ba0.3MnO3layer. We have also studied the magnetic homogeneity of the trilayer structure as a function of the deposition temperature. The perpendicular FMR linewidth, &Ggr;⊥, shows a clear window in the deposition temperature where the linewidth is <50 Oe. However, the parallel linewidth, &Ggr;∥, is nearly ten times larger than &Ggr;⊥with only a weak dependence on the deposition temperature. This broadening of the parallel linewidth compared to the perpendicular linewidth can be explained by invoking a local unidirectional anisotropy in the plane of the film. ©1996 American Institute of Physics.