Electronic properties of disordered perovskite-like ferrites: Coherent potential approach

• Published in: Progress in solid state chemistry 2020-12, Vol.60, p.100284, Article 100284
• Main Authors: Zainullina, Veronika М., Korotin, Мichael А., Kozhevnikov, Victor L.
• Format: Article
• Language: English
• Subjects: Coherent potential approximation; Disordered atomic defects; Disordered perovskite-like ferrites; Electronic structure; Magnetic moments
• ISSN: 0079-6786; 1873-1643
• DOI: 10.1016/j.progsolidstchem.2020.100284

During the past decade, ab initio electronic structure methods have been extensively developed and employed for properties analysis of perovskites ABO3–δ, where A is a large cation and B is typically a 3d metal cation of smaller size. The perovskite structure is capable to withstand ample cation substitutions in both A and B sub-lattices and to simultaneously accommodate large amount of oxygen vacancies (δ). The cation and anion defects result in considerable changes in electronic spectrum features and ensuing properties. In the variety of electronic structure calculation methods, the coherent potential approximation (CPA) is a special approach for studies of systems with disordered defects. The method is designed in order to overcome a number of restrictions that arise at employment of supercells such as defect ordering, limitations for defect types and concentrations, a drastic increase in calculation time with defect concentration, etc. The recently developed implementation of the CPA can be used for calculations of electronic spectrum and properties of solid state systems, including strongly correlated ones with an arbitrary concentration, arrangement and type of atomic structural defects. In this brief review, we consider the capabilities and restrictions of classical CPA-combined methods and represent a novel CPA methodology for the case study of electronic spectra and magnetic moments in several perovskite related disordered ferrites including SrFeO2.5, SrFeO3−δ and solid solutions La1−xSrxFeO3−δ. These complex oxides with strong electronic correlations attract attention as inexpensive, environmentally friendly and robust materials for applications in high-temperature redox technologies, fuel cells, self-cleaning photocatalysis, water splitting, hydrogen and solar power engineering. [Display omitted]