Authors: Qingjie Guo, Qian Chen, Wei Jiang, Bin Lu, Mingming Tian, Ruobai Liu, Xinyu Chen, Zhuoyi Li, Lulu Cao, Fangyuan Zhu, Wen Zhang, Jun Du, Zhongming Zeng, Jinlan Wang, Zhaocong Huang, Yongbing Xu, Ke Xia, Ya Zhai
Published: 2025-03-18
Source: Full article
AbstractField‐free magnetization switching with low critical current density is a fundamental pursuit for spin‐orbit torque (SOT) devices. Here, a novel strategy is provided that utilizes the sperimagnetism of NiFeTb to achieve current‐induced field‐free magnetization switching with high efficiency and controllable chirality. The critical current density required for field‐free magnetization switching is as low as 2.8 × 106 A cm−2, an order of magnitude lower than that in conventional heavy metal‐based magnetic heterostructures. The ultralow critical current density is attributed to the exceptional soft magnetism, the nucleation‐dominant switching characteristic of NiFeTb, and the strong spin Hall effect associated with the large spin‐orbital coupling of Tb 4f electrons. Notably, the switching chirality can be designed by manipulating the history of the in‐plane magnetic field. The field‐free and chirality‐controlled magnetization switching in NiFeTb is facilitated by the symmetry‐broken sperimagnetic structural arrangement. Utilizing the rich intermediate resistance states and non‐volatility of the device, neural network computation is simulated. The findings reveal sperimagnetic rare‐earth‐transition metal alloys as vital candidates for multifunctional, ultra‐low‐power storage and computing applications.