Strain Effects in Narrow-Bandwidth Manganites: The Case of Epitaxial Eu0.7Sr0.3MnO3 Thin Films

We have investigated the strain-dependent magnetic properties of epitaxial narrow-bandwidth manganite, Eu0.7Sr0.3MnO3 (ESMO), thin films on various substrates traversing from compressive (-2.4%) to tensile (+1.5%) strain. The stoichiometry and crystalline quality of the films were confirmed with diffraction and spectroscopic-based characterization. Using field-and temperature-dependent magnetometry, we find that the epitaxial strain acts to suppress the ferromagnetic state, although films under compressive strain retain a greater propensity for ferromagnetic behavior. However, temperature-dependent resistivity reveals that ESMO thin films exhibit a ferromagnetic insulating state in contrast to wide-bandwidth La0.7Sr0.3MnO3 films under a comparable strain. The combination of a highly strain-dependent ferromagnetic state and robust insulating behavior may offer novel applications in spin filtering, sensing, or electronics.