### Abstract

X-ray-absorption fine-structure spectra were measured and analyzed for several FeCo cyanides (Formula presented) K, Rb) which are known to exhibit interesting magnetic properties depending on temperature. X-ray-absorption near-edge structure spectra allow us to confirm very clearly the spin transitions in (Formula presented) and (Formula presented) and to evaluate the composition ratios of (Formula presented) and (Formula presented) species quantitatively. The (Formula presented) ratios are essentially important physical quantities with which to understand magnetic properties. The local structures around Fe and Co atoms were determined by the Fe and Co K-edge extended x-ray-absorption fine-structure spectra. It is confirmed that the local structures around Fe are (Formula presented) (the subscripts denote the coordination numbers) while those around Co are (Formula presented) The first-nearest-neighbor Fe-C distances do not significantly change between (Formula presented) and (Formula presented) species, while the first-nearest-neighbor Co-NO distances are noticeably different between (Formula presented) and (Formula presented) ones. The difference of as much as 0.16-0.20 Å between (Formula presented) and (Formula presented) which corresponds well to that for typical Co tautomeric complexes, causes noticeable change of the lattice constant.

Original language | English |
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Pages (from-to) | 8257-8266 |

Number of pages | 10 |

Journal | Physical Review B - Condensed Matter and Materials Physics |

Volume | 58 |

Issue number | 13 |

DOIs | |

Publication status | Published - Jan 1 1998 |

Externally published | Yes |

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### All Science Journal Classification (ASJC) codes

- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics

### Cite this

*Physical Review B - Condensed Matter and Materials Physics*,

*58*(13), 8257-8266. https://doi.org/10.1103/PhysRevB.58.8257