Abstract
X-ray-absorption fine-structure spectra were measured and analyzed for several FeCo cyanides 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 and and to evaluate the composition ratios of and species quantitatively. The 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 (the subscripts denote the coordination numbers) while those around Co are The first-nearest-neighbor Fe-C distances do not significantly change between and species, while the first-nearest-neighbor Co-NO distances are noticeably different between and ones. The difference of as much as 0.16–0.20 Å between and which corresponds well to that for typical Co tautomeric complexes, causes noticeable change of the lattice constant.
- Received 28 April 1998
DOI:https://doi.org/10.1103/PhysRevB.58.8257
©1998 American Physical Society