Abstract
The structural and magnetic properties of the single-molecule magnet are studied through the analysis of a mixed crystal, where is . X-ray absorption spectra reveal that the Cr ion in is in the valence state and occupies a specific site in the skeleton. High-frequency electron paramagnetic resonance (EPR) spectra are well explained by assuming that is in a ground spin-state of with nearly the same EPR parameter set as for . The lower spin quantum number results in lower barrier height compared to . The magnetization curves indicate a coercive field of for at , nearly half that for . Quantum tunneling of magnetization (QTM) in is observed below the blocking temperature , with the same field interval as for . The magnetization of and in the mixed crystal can be independently manipulated by utilizing the difference between their coercive fields. The resonance fields of QTM in are significantly affected by the magnetization direction of , suggesting the effect of dipolar-biased tunneling.
2 More- Received 9 January 2004
DOI:https://doi.org/10.1103/PhysRevB.70.104427
©2004 American Physical Society