Dielectric Activity and Ferroelectricity in Piezoelectric Semiconductor Li-Doped ZnO

Abstract

Temperature dependences of dielectric constants, specific heat and D–E hysteresis loops of Li-doped zinc oxide ceramics were investigated. A new dielectric anomaly was found at 330 K in Zn_1-xLi_xO with x=0.17. A cusp-like anomaly was also found in specific heat. A ferroelectric D–E hysteresis loop was successfully observed for the first time. These observations suggest that replacement of host Zn ions by small Li ions induces a ferroelectric phase in the wurtzite-type ZnO piezoelectric semiconductor. This material is a candidate for ferroelectric thin films in integrated ferroelectric devices.