Observation of room-temperature multiferroicity with strong magnetoelectric coupling in hafnia thin films.

Zhang, Haiyi; Bu, Haifeng; Zhang, Dehe; Tu, Yuchen; Li, Yaoxin; Shen, Zhijian; Pan, Weijin; Guan, Zeyu et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

HfO<sub>2</sub>-based ferroelectrics have emerged as promising candidates for next-generation information devices due to their excellent compatibility with complementary metal oxide semiconductor technology. However, achieving room-temperature multiferroicity in single-phase HfO<sub>2</sub>-based materials remains a rewarding yet challenging goal. Here, we report the discovery of room temperature multiferroicity in single-phase Cr-doped HfO<sub>2</sub> films. We demonstrate a direct correlation between ferroelectric and ferromagnetic orders; films with stronger ferromagnetism exhibit enhanced ferroelectricity. Crucially, the application of external magnetic fields induces a significant boost in both ferroelectric polarization and piezoresponse amplitude. A giant magnetoelectric coupling coefficient of ~100 Vcm<sup>-1</sup>Oe<sup>-1</sup> is obtained, surpassing those of most previously reported single-phase multiferroic materials at room temperature. Our results not only establish Cr-doped HfO<sub>2</sub> films as a promising platform for exploring emergent multiferroic phenomena but also pave the way for a new class of silicon-compatible magnetoelectric devices.