Project Details
Projekt
Cation Ordering by Atomic Layer Engineering of Strongly Correlated Oxides
Subject Area
Experimental Condensed Matter Physics
Synthesis and Properties of Functional Materials
Synthesis and Properties of Functional Materials
Term
from 2017 to 2021
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 387838520
The proposal addresses chemical substitutional disorder on A- and B-sites in thin films of strongly correlated perovskite oxides with general formula ABO3. Because of strong electronic correlations and electron-phonon coupling these materials display coupled phase transitions, underlying scientifically interesting phenomena and technologically promising functionalities. Cation or quenched disorder, arising as a result of chemical substitution (doping), strongly affects phase transitions, suppressing their critical temperature and masking the intrinsic fundamental behavior of correlated oxides.We propose a growth approach for the cation-ordered films of correlated oxides based on in-situ controlled atomic layer epitaxy and strain engineering, both realized within a metalorganic aerosol deposition (MAD) technique. The A-site ordered modifications of three- (3D) and two-dimensional (2D, Ruddlesden-Popper) perovskites as well as B-site ordered double perovskites will be epitaxially grown in the form of artificial superlattices, in which a layered and/or checker-board types of cation ordering will be realized. By using lattice-matched and lattice-mismatched substrates, coherently strained and strain-free ordered perovskites will be obtained. Global and local crystalline structure and chemical composition will be analyzed by X-ray diffraction/reflectometry as well as by scanning tunneling and transmission electron microscopy down to the atomic scale. Distributions of local lattice strain and electronic charge will be quantified at the nanoscale and atomic scale. The impact of cation ordering on the improvement of electronic and magnetic properties and on the increase of Tc in artificially ordered perovskite lattices will be disclosed.
DFG Programme
Research Grants
