Abstract
Full-potential density-functional calculations show that the electronic structure of one-dimensional ferrimagnetic varies from metal to half metal to insulator as its magnetic ordering changes from the ferrimagnetic through the ferromagnetic to the paramagnetic state. The present Letter is the first to establish the occurrence of half metallicity in one-dimensional oxides. Moreover, the electronic and magnetic properties of this material can be tuned by substitution of Y for Ca, as shown by our detailed study on (, 0.3, 0.75, and 1). The Co ions are in two different valence states [ (low-spin) and (high-spin)], and hence the occurrence of charge ordering in addition to spin ordering is established. For specific Y concentrations we predict a rarely seen combination of ferromagnetic and insulating behavior.
- Received 12 March 2003
DOI:https://doi.org/10.1103/PhysRevLett.91.186404
©2003 American Physical Society