Epitaxial stabilization of ultra thin films of high entropy perovskite
Abstract
High entropy oxides (HEOs) are a class of materials, containing equimolar portions of five or more transition metal and/or rare-earth elements. We report here about the layer-by-layer growth of HEO [( La 0.2 Pr 0.2 Nd 0.2 Sm 0.2 Eu 0.2 )NiO3] thin films on NdGaO3 substrates by pulsed laser deposition. The combined characterizations with in situ reflection high energy electron diffraction, atomic force microscopy, and x-ray diffraction affirm the single crystalline nature of the film with smooth surface morphology. The desired +3 oxidation of Ni has been confirmed by an element sensitive x-ray absorption spectroscopy measurement. Temperature dependent electrical transport measurements revealed a first order metal-insulator transition with the transition temperature very similar to the undoped NdNiO3. Since both these systems have a comparable tolerance factor, this work demonstrates that the electronic behaviors of A-site disordered perovskite-HEOs are primarily controlled by the average tolerance factor.
- Publication:
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Applied Physics Letters
- Pub Date:
- February 2020
- DOI:
- 10.1063/1.5133710
- arXiv:
- arXiv:1911.03866
- Bibcode:
- 2020ApPhL.116g1601P
- Keywords:
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- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 4 figures