A Complete High-to-Low spin state Transition of Trivalent Cobalt Ion in Octahedral Symmetry in SrCo0.5Ru0.5O3-δ
- 15 January 2014
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 136 (4), 1514-1519
- https://doi.org/10.1021/ja4114006
Abstract
The complex metal oxide SrCo0.5Ru0.5O3-δ possesses a slightly distorted perovskite crystal structure. Its insulating nature infers a well-defined charge distribution, and the six-fold coordinated transition metals have the oxidation states +5 for ruthenium and +3 for cobalt as observed by X-ray spectroscopy. We have discovered that Co3+ ion is purely high-spin at room temperature, which is unique for a Co3+ in an octahedral oxygen surrounding. We attribute this to the crystal field interaction being weaker than the Hund’s-rule exchange due to a relatively large mean Co–O distances of 1.98(2) Å, as obtained by EXAFS and X-ray diffraction experiments. A gradual high-to-low spin state transition is completed by applying high hydrostatic pressure of up to 40 GPa. Across this spin state transition, the Co Kβ emission spectra can be fully explained by a weighted sum of the high-spin and low-spin spectra. Thereby is the much debated intermediate spin state of Co3+ absent in this material. These results allow us to draw an energy diagram depicting relative stabilities of the high-, intermediate-, and low-spin states as functions of the metal–oxygen bond length for a Co3+ ion in an octahedral coordinationThis publication has 45 references indexed in Scilit:
- Reversible Switching of a Cobalt Complex by Thermal, Pressure, and Electrochemical Stimuli: Abrupt, Complete, Hysteretic Spin CrossoverJournal of the American Chemical Society, 2011
- Spin-crossover in cobalt(II) imine complexesCoordination Chemistry Reviews, 2007
- Spin State Transition inStudied Using Soft X-ray Absorption Spectroscopy and Magnetic Circular DichroismPhysical Review Letters, 2006
- Pressure-induced Spin State Transition in Co–Fe CyanideJournal of the Physics Society Japan, 2004
- Solution and Solid-State Spin-Crossover Behavior in a Pseudotetrahedral d7 IonJournal of the American Chemical Society, 2003
- Synthesis and Properties of the Structurally One-Dimensional Cobalt Oxide Ba1−xSrxCoO3 (0≤x≤0.5)Journal of Solid State Chemistry, 1999
- Valence electron distribution in La2Li1/2Cu1/2O4, Nd2Li1/2Ni1/2O4, and La2Li1/2Co1/2O4Chemical Physics Letters, 1998
- X-ray photoelectron spectrum of low-spin Co(III) in LiCoO2Journal of Solid State Chemistry, 1978
- Complex vs Band Formation in Perovskite OxidesJournal of Applied Physics, 1965
- UNUSUAL MAGNETIC PROPERTIES OF SOME SIX-COÖRDINATE COBALT(II) COMPLEXES1 —ELECTRONIC ISOMERSJournal of the American Chemical Society, 1961