Misfit strain induced lattice distortions in heteroepitaxially grown LaxCa1−xMnO3 thin films studied by extended x-ray absorption fine structure and high-resolution x-ray diffraction

Abstract

Mn–O and Mn–Mn interatomic distances were determined in LaxCa1−xMnO3 films grown heteroepitaxially on single crystal SrTiO3 and LaAlO3 substrates by molecular beam epitaxy. Mn–O bond lengths were found to be fixed at ∼1.975 Å for both types of substrates, while the Mn–Mn distance was detected to be larger for films grown on SrTiO3 substrates than for films grown on LaAlO3. The deviation of Mn–Mn interatomic distances, and subsequently Mn–O–Mn bond angles, in epitaxial LaxCa1−xMnO3 films is attributed to the misfit strain: compressive for LaAlO3 and tensile for SrTiO3 substrates.