Coexistence of ferroelectricity and ferromagnetism in Ni-doped Al0.7Sc0.3N thin films

Abstract

Development of multiferroic materials with the capability of compatibility with the current semiconductor technology is of interest for practical applications. Recent experimental discovery of robust ferroelectricity in CMOS-compatible III-nitrides offers an alluring opportunity to construct multiferroic nitrides through chemical-doping engineering. We here reported the coexistence of ferroelectricity and ferromagnetism in Ni-doped Al0.7Sc0.3N thin films. It is found that apart from the promising ferroelectric properties, including a square-like polarization–electric field (P–E) hysteresis loop with a large coercive field (∼3 MV/cm) and high remanent polarizations (∼100 μC/cm2), the films also exhibit room-temperature ferromagnetism, with a saturation magnetization of ∼8 emu/cm3. Additionally, the magneto-dielectric effect has also been experimentally confirmed. Our work provides a reference for subsequent research on nitride multiferroic materials and related applications.