Transport anisotropy in biaxially strained La(2/3)Ca(1/3)MnO(3) thin films

TL;DR

This study investigates how biaxial strain affects transport anisotropy in La(2/3)Ca(1/3)MnO(3) thin films, revealing a transition from metallic to insulating behavior perpendicular to the strain plane due to orbital ordering.

Contribution

It demonstrates the strain-induced transition from an orbitally disordered to an orbitally ordered state affecting transport properties in manganite thin films.

Findings

Metallic behavior within the plane of strain.

Insulating behavior perpendicular to the strain plane.

Non-linear current-voltage characteristics perpendicular to the strain plane.

Abstract

Due to the complex interplay of magnetic, structural, electronic, and orbital degrees of freedom, biaxial strain is known to play an essential role in the doped manganites. For coherently strained La(2/3)Ca(1/3)MnO(3) thin films grown on SrTiO(3) substrates, we measured the magnetotransport properties both parallel and perpendicular to the substrate and found an anomaly of the electrical transport properties. Whereas metallic behavior is found within the plane of biaxial strain, for transport perpendicular to this plane an insulating behavior and non-linear current-voltage characteristics (IVCs) are observed. The most natural explanation of this anisotropy is a strain induced transition from an orbitally disordered ferromagnetic state to an orbitally ordered state associated with antiferromagnetic stacking of ferromagnetic manganese oxide planes.