Thickness dependence of stress in La0.9Sr0.1MnO3 monocrystalline nanofilms using synchrotron radiation X-ray diffraction

Residual stresses in ultrathin La0.9Sr0.1MnO3 (LSMO) films with various thicknesses of 8–40 nm were measured quantitatively via synchrotron radiation X-ray diffraction. By fitting the strain versus sin2ψsin2ψ plots the residual stresses in the nanofilms were obtained. With increasing film thickness, both the in- and out-of-plane stresses decreased for strain relaxation. The strains of LSMO nanofilms on miscut SrTiO3 (STO) substrates were weaker than those on exact-cut ones with same thickness, which indicates that the crystallization in nanofilms on miscut SrTiO3 was more perfect than that on exact-cut SrTiO3. The mechanism is discussed briefly based on the minimization of surface energy and strain energy.

► La0.9Sr0.1MnO3 nanofilms were deposited by laser molecular beam epitaxy. ► LSMO nanofilms have a pseudo-cubic structure with a perovskite unit cell. ► We focus on the stress in ultrathin LSMO/STO film with thicknesses 8–40 nm. ► Crystalline quality of the LSMO films on miscut substrates is superior. ► Film thickness affects the stress strongly.