Strain-dependent magnetotransport properties of La_0.9Sr_0.1MnO₃epitaxial films on SrTiO₃and LaAlO₃substrates

Abstract

The strain effect on the magnetotransport properties in La0.9Sr0.1MnO3 films epitaxially deposited on SrTiO3 (STO) and LaAlO3 (LAO) substrates, is demonstrated. Large compressive strain is formed in the films on the LAO substrate; however, that on the STO is subject to a small tensile strain. Strain relaxation of films grown on both substrates results in the formation of a spin-canted antiferromagnetic (AFM) insulative phase, causing the increase in resistivity with decreasing temperature. The characteristics of the AFM insulative phase become apparent with increasing film thickness, which leads to a clear AFM transition in the films grown on LAO and a reduction of magnetization and Curie temperature in those on STO. The magnetoresistance effect of the films is also consistent with the above results.

Surface characterization of ultrathin La0.75Sr0.25MnO3 epitaxial films on SrTiO3 substrate

“…It has been attributed to the structural and magnetic modifications at the interface between the film and the substrate [3]. The strain of manganite films epitaxially grown on perovskite substrate is dependent on film thickness as well as its lattice mismatch to the underlying substrate [4]. For example, tensile strain suppresses the ferromagnetism and reduces the ferromagnetic Curie temperature, which is realized by the Jahn-Teller distortion of MnO 6 octahedra [5].…”