Effects of oxygen-reducing atmosphere annealing on LaMnO${}_3$ epitaxial thin films

Abstract

We investigated the effects of annealing on LaMnO${}_3$ epitaxial thin films grown by pulsed laser deposition and propose an efficient method of characterizing their stoichiometry. Structural, magnetic, and optical properties coherently indicate non-stoichiometric ferromagnetic and semiconducting phases for as-grown LaMnO${}_3$ films. By annealing in an oxygen-reducing atmosphere, we recovered the antiferromagnetic and insulating phases of bulk-like stoichiometric LaMnO${}_3$. We show that non-destructive optical spectroscopy at room temperature is one of the most convenient tools for identifying the phases of LaMnO${}_3$ films. Our results serve as a prerequisite in studying LaMnO${}_3$ based heterostructures grown by pulsed laser deposition.

10 pages including 3 figures, accepted in J. Phys. D: Appl. Phys