Epitaxial growth and structure of LaVO3 and PrVO3 thin films

Abstract

We report on the epitaxial growth of PrVO 3 and LaVO 3 by molecular beam epitaxy on (001)-oriented SrTiO 3 substrates. We show that a high control of the deposition is achieved and leads to a highly reproducible layer-by-layer growth mode. We evidence also the effect of epitaxial strain on the magnetic properties of the epitaxial films. High-resolution transmission electron microscopy and scanning transmission electron microscopy observations reveal that an antipolar motion of the rare earth atoms exists in both LaVO 3 and PrVO 3 thin films. The investigation of the structural distortions and atomic displacements in the vanadate thin films may be generalized to other orthorhombic perovskite oxides and contributes to the search of ferroelectricity by design in symmetry-breaking magnetic oxide superlattices.

Growth and Characterization of Off-Stoichiometric LaVO$_3$ Thin Films

“…The film thickness was around 200 nm unless indicated otherwise, i.e., L3: 350 nm, as determined from TEM and from the number of pulses used during growth. The dashed line is the expected lattice parameter based on a Poisson ratio of ν =0.398 30,31 and epitaxial strain of ε || = -0.5 %. films are similar in thickness (around 200 nm), such a difference indicates that the structure in the La-rich film is less coherent, which is consistent with the structural domains observed in TEM (see Fig.…”

“…From structural characterizations using x-ray diffraction (XRD) and transmission electron microscopy (TEM), we learn that the amount of elongation of the out-of-plane lattice constant depends on the La:V stoichiometry. The V-rich (La-rich) films have a smaller (larger) unit cell volume compared to the expected unit cell volume based on the reported Poisson ratio for bulk LVO and the epitaxial strain 30,31 . Furthermore, the film unit cells are not single-oriented, similar to previous reports 30 .…”

“…The V-rich (La-rich) films have a smaller (larger) unit cell volume compared to the expected unit cell volume based on the reported Poisson ratio for bulk LVO and the epitaxial strain 30,31 . Furthermore, the film unit cells are not single-oriented, similar to previous reports 30 . From absorption measurements (see Fig.…”