Magnetic phase coupled to an electric memory state in d~0 oxide ZrO_2 films

摘要

It is quite interesting to develop a multifunctional device using a single material with a simple structure. One of the possible candidates could be multiferroics, which are both ferroelectric and magnetic. By taking advantage of the strong spin-charge coupling, the electric field can control the magnetic polarization and the magnetic field can control the electric polarization. However, these multiferroics are not yet attractive for practical applications because none of the existing materials combine large and robust electric and magnetic polarizations at room temperature. Here, we report an unusual functional material showing a magnetic phase strongly coupled to an electric memory state at room temperature. An oxygen-vacant ZrO_2 thin film generates bistable resistive switching between high-resistance (HR) and low-resistance (LR) states by applying external voltage, and it is ferromagnetic at the HR state but nonmagnetic at the LR state. This unique feature is applicable to unusual functional devices, such as electric-field-controlled magnetic data storage devices.