Substrate-induced strain effects on Pr_{0.6}Ca_{0.4}MnO_{3} films

TL;DR

This study investigates how substrate-induced strain affects the structural, electronic, and magnetic properties of Pr_{0.6}Ca_{0.4}MnO_{3} films, revealing strain-dependent differences in charge and orbital ordering and their relation to magnetic behavior.

Contribution

It demonstrates the influence of substrate-induced strain on the crystal symmetry and ordering phenomena in Pr_{0.6}Ca_{0.4}MnO_{3} films, highlighting the importance of Mn--O--Mn bond angles.

Findings

Compressive strain stabilizes low-temperature charge and orbital ordering.

Tensile strain weakens or suppresses charge and orbital ordering.

Lattice distortion linked to orbital ordering correlates with antiferromagnetic transition.

Abstract

We report the characterization of the crystal structure, low-temperature charge and orbital ordering, transport, and magnetization of Pr_{0.6}Ca_{0.4}MnO_{3} films grown on LaAlO_{3}, NdGaO_{3}, and SrTiO_{3} substrates, which provide compressive (LaAlO_{3}) and tensile (NdGaO_{3} and SrTiO_{3}) strain. The films are observed to exhibit different crystallographic symmetries than the bulk material, and the low-temperature ordering is found to be more robust under compressive-- as opposed to tensile-- strain. In fact, bulk-like charge and orbital ordering is not observed in the film grown on NdGaO_{3}, which is the substrate that provides the least amount of nominal and measured, but tensile, strain. This result suggests the importance of the role played by the Mn--O--Mn bond angles in the formation of charge and orbital ordering at low temperatures. Finally, in the film grown on LaAlO_{3}, a connection between the lattice distortion associated with orbital ordering and the onset of antiferromagnetism is reported.