Local mapping of strain at grain boundaries in colossal magnetoresistive films using x-ray microdiffraction

Using x-ray submicrobeam, we spatially mapped the strain in epitaxial La1−xSrxMnO3 films grown on SrTiO3(001) bicrystal substrates. Our results show that there is an elastic strain gradient at the artificial grain boundary, which decays over a length scale of ∼1 μm. The tensile strain at the interior of the grain—due to the lattice mismatch between La1−xSrxMnO3 and SrTiO3—relaxes as the film nears the grain boundary, yielding a grain boundary lattice constant which approaches the value of that in bulk La1−xSrxMnO3.