| 研究実績の概要 |
Orbital angular momentum is the main physical contribution to magnetic anisotropy related magnetic and spintronic properties. However, there is no effective way to control the contribution of orbital angular momentum. In this project, we designed a cobalt complex bearing nitrate ligands exhibits magnetic bistability by changing its coordination number from six to seven. The change in the magnitude of the magnetic moment is 10-11% of the original magnetization value of the six-coordinate Co(II) compound. The ab initio calculations show that the formation of the seventh bond modulates the ligand field causing an increase in the energy of the first singly occupied d-orbital and the breaking of the bond conversely lowers its energy, which induces effective quenching and restoration of the orbital angular momentum. This change is the largest reported value for any crystalline molecular material that exhibits thermally reversible orbital angular momentum switching. By combining detailed single crystal magnetization measurements with synchrotron X-ray magnetic circular dichroism and X-ray absorption spectroscopy, we have gotten a much more precise insight into the underlying magnetism and electronic structure. This result is consistent well with that of the theoretical calculations. This technique of switching coordination number could be widely used to control various physical properties, not only orbital angular momentum. For this work, we have already submitted the research paper to the Journal of the American Chemical Society.
|
