Mesoscopic theory of defect ordering–disordering transitions in thin oxide films

• Published in: Scientific reports Vol. 10; no. 1; p. 22377
• Main Authors: Morozovska, Anna N., Eliseev, Eugene A., Karpinsky, Dmitry V., Silibin, Maxim V., Vasudevan, Rama, Kalinin, Sergei V., Genenko, Yuri A.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 24.12.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/1005; 639/301/1034; 639/301/119; 639/301/357; Casting; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; condensed-matter physics; Defects; Humanities and Social Sciences; materials for devices; multidisciplinary; nanoscale materials; Phase diagrams; Science; Science (multidisciplinary); theory and computation
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-79482-w

Ordering of mobile defects in functional materials can give rise to fundamentally new phases possessing ferroic and multiferroic functionalities. Here we develop the Landau theory for strain induced ordering of defects (e.g. oxygen vacancies) in thin oxide films, considering both the ordering and wavelength of possible instabilities. Using derived analytical expressions for the energies of various defect-ordered states, we calculated and analyzed phase diagrams dependence on the film-substrate mismatch strain, concentration of defects, and Vegard coefficients. Obtained results open possibilities to create and control superstructures of ordered defects in thin oxide films by selecting the appropriate substrate and defect concentration.