thin films*

The perovskite oxide LaVO₃ is an archetypical Mott insulator which undergoes a antiferromagnetic (AFM) orbital and spin order transition at ~140 K, concomitant with a structural distortion from the high temperature Pbnm structure ¹. In this talk, we report on the arrangement of coexisting phases stabilized by epitaxial strain imposed by the substrate using a combination of synchrotron x-ray diffraction², x-ray diffraction microscopy³ and scanning transmission electron microscopy. Coherently strained LaVO₃ thin films were grown by hybrid molecular beam epitaxy (hMBE)⁴ on NdGaO₃ and GdScO₃. It is found that different order and phase arrangement occurs at room temperature and low temperatures at dramatically different length scales ranging from about 3 nm to 300 nm. We discuss the nature and origin of these ordered phases, which have not been observed in bulk LaVO₃, in light of the structural constraints imposed by the substrate.

1. Bordet, P. et al. J. Solid State Chem. 106, 253–270 (1993).
2. Brahlek, M., et al. Appl. Phys. 1211, (2017).
3. Laanait, N. et al. J. Synchrotron Radiat. 21, 1252–1261 (2014).
4. Zhang, H.-T. et al. ACS Appl. Mater. Interfaces 9, 12556–12562 (2017).