Ground-state structure, orbital ordering and metal-insulator transition in double-perovskite PrBaMn2O6

Streltsov, S. V.; Ryltsev, R. E.; Chtchelkatchev, N. M.

doi:10.1016/j.jallcom.2022.165150

Cited by 13 publications

(1 citation statement)

References 47 publications

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“…The geometry optimization convergence threshold is 10 −2 eV Å −1 (determined from the forces acting on atoms). A resulting atomic structure after atomic relaxation depends on the initial structure and on the initial guess for electron density [56].…”

Section: Model and Calculation Detailsmentioning

confidence: 99%

Frenkel pair formation energy for cubic Fe₃O₄ in DFT + U calculations

Шутикова¹,

Stegaĭlov²

2022

J. Phys.: Condens. Matter

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The cubic phase of magnetite is stabilized above the Verwey transition temperature of about 120~K via a complex electron-phonon interaction that is still not very well understood. In this work using the DFT+U method we describe our attempt to calculate point defect formation energies for this cubic phase in the static approximation. The electronic structure calculations and atomic relaxation peculiarities are discussed in this context. Only the cubic phase model with a small band gap and charge disproportionation (Fe$^{2+}$/ Fe$^{3+}$) gives an adequate point defect formation energies, not the semi-metallic model. The relaxation of the local defect atomic structure and the relaxation of the surrounding crystal matrix are analysed. Point defects cause only local perturbations of atomic positions and charge-orbital order. After analysis of the supercell size effects for up to 448 atoms, we justify the use of small supercells with 56 atoms to make calculations for the cubic phase. The extensive experimental results of Dieckmann et al. on defects in magnetite at high temperature are deployed for comparison of our DFT+U results on Frenkel pair formation energies.

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Section: Model and Calculation Detailsmentioning

confidence: 99%