title: Mechanism of magnetic moment collapse under pressure in ferropericlase.
abstract: We propose a new scenario for the magnetic collapse under pressure in ferropericlase (FP) (Fe(1/4)Mg(3/4))O without the presence of intermediate spin state, which contradicts the mechanism proposed in (2013 Phys. Rev. B 87 165113). This scenario is supported by results of combined local density approximation + dynamical mean-field theory method calculations for the paramagnetic phase at ambient and high pressures. At ambient pressure, calculation gave (Fe(1/4)Mg(3/4))O as an insulator with Fe 3d-shell in high-spin state. Experimentally observed high-spin to low-spin state transition of the Fe(2+) ion in the pressure range of 35-75 GPa is successfully reproduced in our calculations. The spin crossover is characterized by coexistence of Fe(2+) ions in high and low spin state but intermediate spin state is absent in the whole pressure range. Moreover, the probability of Fe ion d(7) onfiguration with S = 1 grows with pressure due to shortening of metal-oxygen distance. Also, no metal-insulator transition was obtained up to the pressure 140 GPa in agreement with experiment.
authors.affiliation: M.N. Miheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, 620137 Yekaterinburg, Russia.
authors.forename: N A
authors.initials: NA
authors.lastname: Skorikov
authors.forename: A O
authors.initials: AO
authors.lastname: Shorikov
authors.forename: S L
authors.initials: SL
authors.lastname: Skornyakov
authors.forename: M A
authors.initials: MA
authors.lastname: Korotin
authors.forename: V I
authors.initials: VI
authors.lastname: Anisimov
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D005296:Ferrous Compounds / Q000737:chemistry*; D008277:Magnesium Oxide / Q000737:chemistry*; D008280:Magnetics; D008958:Models, Molecular; D011312:Pressure; D011789:Quantum Theory; D015204:Spectroscopy, Mossbauer
chemical_list: D005296:Ferrous Compounds; D008277:Magnesium Oxide