title: Dual field effects in electrolyte-gated spinel ferrite: electrostatic carrier doping and redox reactions.
abstract: Controlling the electronic properties of functional oxide materials via external electric fields has attracted increasing attention as a key technology for next-generation electronics. For transition-metal oxides with metallic carrier densities, the electric-field effect with ionic liquid electrolytes has been widely used because of the enormous carrier doping capabilities. The gate-induced redox reactions revealed by recent investigations have, however, highlighted the complex nature of the electric-field effect. Here, we use the gate-induced conductance modulation of spinel ZnxFe₃₋xO₄ to demonstrate the dual contributions of volatile and non-volatile field effects arising from electronic carrier doping and redox reactions. These two contributions are found to change in opposite senses depending on the Zn content x; virtual electronic and chemical field effects are observed at appropriate Zn compositions. The tuning of field-effect characteristics via composition engineering should be extremely useful for fabricating high-performance oxide field-effect devices.
authors: The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan.
authors: Takashi
authors: T
authors: Ichimura
authors: The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan.
authors: Kohei
authors: K
authors: Fujiwara
authors: The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan.
authors: Hidekazu
authors: H
authors: Tanaka