Electrochemical Control of the Magnetic Moment of CrO[sub 2]

The magnetic moment of the half-metallic ferromagnetic oxide has been modified via electrochemical lithiation. In the low-Li regime, below about in , a large change in magnetization of per 0.1 Li/formula unit is obtained, in reasonable agreement with a model based on the change in oxidation state of the Cr ions. The change in magnetization is partly reversible, especially for . The kinetics and reversibility of the process are improved at , and Li contents up to could be inserted. At these concentrations the room-temperature moment is reduced to of its initial value. This decrease is irreversible, due to disruption of the rutile crystal structure of the .