Spin transitions — metal ions changing from high- to low-spin states — can be triggered by a range of stimuli and have normally only been observed in octahedrally coordinated ions. Now, a four-coordinate, square-planar iron(II) compound, SrFeO2, exhibits such a spin transition, accompanied by a transition from an antiferromagnetic insulator to a ferromagnetic half-metal.
- T. Kawakami
- Y. Tsujimoto
- M. Takano