Strain effect on electronic transport and ferromagnetic transition temperature in La$_{0.9}$Sr$_{0.1}$MnO$_{3}$ thin films

TL;DR

This study investigates how strain influences the electronic transport and ferromagnetic transition temperature in La$_{0.9}$Sr$_{0.1}$MnO$_{3}$ thin films, revealing that compressive strain enhances $T_{c}$ and affects polaronic properties.

Contribution

It provides a systematic analysis of strain effects on magnetic and transport properties, highlighting the role of electron-phonon coupling in thin films.

Findings

Decreasing film thickness enhances $T_{c}$ due to compressive strain.

Resistivity behavior consistent with small polaronic hopping above 165 K.

Strain dependence of $T_{c}$ linked to strain-induced electron-phonon coupling.

Abstract

We report on a systematic study of strain effects on the transport properties and the ferromagnetic transition temperature $T_{c}$ of high-quality La$_{0.9}$Sr$_{0.1}$MnO$_{3}$ thin films epitaxially grown on (100) SrTiO$_{3}$ substrates. Both the magnetization and the resistivity are critically dependent on the film thickness. $T_{c}$ is enhanced with decreasing the film thickness due to the compressive stain produced by lattice mismatch. The resistivity above 165 K of the films with various thicknesses is consistent with small polaronic hopping conductivity. The polaronic formation energy $E_{P}$ is reduced with the decrease of film thickness. We found that the strain dependence of $T_{c}$ mainly results from the strain-induced electron-phonon coupling. The strain effect on $E_{P}$ is in good agreement with the theoretical predictions.