Spin-state transition in Ba2Co9O14

Abstract

Abstract

Experimental and Theoretical Soft X‐Ray Absorption Study on Co3+ Ion Spin States in Sr2−xCaxCoO3F

“…The O‐ K XAS spectrum of Sr 1.7 Ca 0.3 CoO 3 F and those of Sr 2 CoO 3 F, SrCoO 3 Cl and EuCoO 3 are presented in Figure . Here, the spectral features in the 527–532 eV energy range represent transitions from O core 1s level to its unoccupied 2p states . The similarity among spectra for Sr 1.7 Ca 0.3 CoO 3 F, Sr 2 CoO 3 F, and SrCoO 3 Cl again suggests the HS Co 3+ ground state.…”

“…O‐K XAS Study of the Co Spin State in Sr 1.7 Ca 0.3 CoO 3 F : More spectroscopic evidences for the HS nature of Co 3+ in Sr 1.7 Ca 0.3 CoO 3 F can be found from O‐ K spectra as shown in Figure owing to the hybridization between Co‐3d and O‐2p . The O‐ K XAS spectrum of Sr 1.7 Ca 0.3 CoO 3 F and those of Sr 2 CoO 3 F, SrCoO 3 Cl and EuCoO 3 are presented in Figure .…”

Phase transition of square-lattice antiferromagnets at finite temperature

“…If a two-dimensional AFM system has no any anisotropy, there will be no spontaneous sublattice magnetizations in it [24,25]. It was indeed possible for the single-ion anisotropy to appear in real materials [26]. We term the exchanges J 1 and J 2 and anisotropy D as Hamiltonian parameters.…”

Large Magnetoresistance in Magnetically Coupled SrRuO3 –CoFe2O4 Self‐Assembled Nanostructures

“…The X‐ray absorption spectroscopy (XAS) measurements at the Co‐L 2,3 , Fe‐L 2,3 , and Ru‐L 3 edges were then performed to realize the electronic structural information and the valence of the Co, Fe, and Ru ions. As for the Co spectrum in the SRO–CFO nanostructures shown in Figure a, the profile compared with the standard sample of LaCoO 3 and CoO strongly suggests the presence of Co 2+ and low‐spin Co 3+ ions in this system, where the main peaks of Co 2+ and Co 3+ are assigned at 779 and 780.7 eV, respectively 29–31. The Fe‐L 2,3 XAS results (Figure 4b) also establish that the valence of Fe ions are all 3+ in the SRO–CFO nanostructure.…”