2024/08/19 by Liang Si, Peitao Liu, Si, Liang +3 · 2 citations
Materials Science · #FOS: Physical sciences #Ferroelectric and Piezoelectric Materials #Magnetic and transport properties of perovskites and related materials #Materials Science (cond-mat.mtrl-sci) #Strongly Correlated Electrons (cond-mat.str-el) #X-ray Diffraction in Crystallography
paper · pdf · doi:10.48550/arxiv.2408.10440
openalex publication_date 2024/08/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Determining the strength of electronic correlations of correlated electrons plays important roles in accurately describing the electronic structures and physical properties of transition-metal (TM) perovskite oxides. Here, we study the evolution of electronic interaction parameters as a function of d-electron occupancy in an extended class of TM perovskite oxides ABO3 (A=Sr, Ca, and B=3d-5d TM elements) using the constrained random-phase-approximation method adopting two distinct models: t2g-t2g and d-dp. For SrBO3 with B=Fe, Ru, and Ir, the t2g-t2g model faces critical challenges, as the low-energy Hamiltonian spanning t2g manifolds is ill-defined. The t2g-t2g model suggests that, for early ABO3 series (B=d1-d3), the bare Coulomb interaction parameters V remain nearly constant due to the competition between extended t2g Wannier orbitals and bandwidth reduction. As the d-electron filling increases, both partially screened Coulomb interaction parameters U and fully screened Coulomb interaction parameters W decrease, which are attributed to enhanced eg-t2g and eg-p screenings. In contrast to the t2g-t2g model, the d-dp model effectively handles both early and late ABO3 perovskites and reveals different trends. Specifically, V varies inversely with the spreads of d-orbitals. W reaches its minimum at the d3 occupancy due to an interplay between increasing d-orbital localization and increasing screening effects. An unusual trend is observed for U, with local maxima at both d1 and d4 occupations. This can be understood from two aspects: (1) the increasing full screening effects from d1 to d3 and (2) the strongest d-d and the weakest d-p screening effects near d4 for SrBO3.