[论文解读] Electrically Accessible Metamagnetic Transition via a Doping-Induced Low-Energy Magnetic State in Antiferromagnetic Insulator RFeO3

Wanting Yang, Haohuan Peng+8 more|arXiv (Cornell University)|Jan 23, 2026

Multiferroics and related materials被引用 0

一句话总结

论文在掺杂的反铁磁绝缘体 Ho0.5Dy0.5FeO3 中展示了一种可电控的亚磁转变，通过稳定一个低能量的中间磁态来实现低磁场下的切换，自旋霍尔磁阻信号指示转变。

ABSTRACT

Low-energy antiferromagnetic phase transitions offer an appealing platform for low-power spintronic functionalities, yet their direct electrical access in insulating antiferromagnets remains challenging, particularly in the low-field regime where subtle Neeel vector reorientations dominate. Here, we demonstrate that targeted rare-earth-site engineering enables an electrically accessible metamagnetic transition in the insulating orthoferrite Ho0.5Dy0.5FeO3. By combining the distinct spin-reorientation sequences of DyFeO3 and HoFeO3, Dy substitution stabilizes a dual spin-reorientation pathway, hosting an intermediate state with a reduced energy barrier. This low-energy antiferromagnetic state can be tuned into the weak-ferromagnetic state under low magnetic fields. The critical field decreases with increasing temperature, providing a favorable window for functional manipulation. Both longitudinal and transverse spin Hall magnetoresistance channels exhibit clear and reproducible signatures of the metamagnetic transitions. Owing to the enhanced sensitivity of the transverse channel, additional low-field features are resolved, reflecting the projection of the Neel vector onto the spin-accumulation direction. Electrical transport measurements correlate directly with the magnetically determined phase boundaries, establishing a purely electrical access to low-energy phase transitions and to illustrate a viable pathway for exploring low-power spin dynamics in insulating oxide antiferromagnets.

研究动机与目标

• 通过实现对低功耗自旋电子学控制的绝缘抗铁磁体的低能量磁转变来提供动机。
• 研究稀土位点工程（Dy/Ho 混合）如何改变 RFeO3 的自旋定向路径。
• 展示掺杂诱导的中间反铁磁态，其能垒降低，从而实现亚磁切换。
• 将电输运信号与磁性界定的相界相关联，以建立对磁转变的电学访问。

提出的方法

• 用目标稀土位点组成合成 Ho0.5Dy0.5FeO3。
• 表征 DyFeO3 和 HoFeO3 的自旋定向序列，以识别双路径行为。
• 在低磁场下驱动转变并通过纵向与横向自旋霍尔磁阻进行监测。
• 分析中间低能态如何降低亚磁切换的能垒。
• 将电输运测量与磁性确定的相边界相关联，以验证对磁态的电控。

实验结果

研究问题

• RQ1 稀土位点工程是否能在绝缘抗铁磁体中实现可电控的亚磁转变？
• RQ2 用 Dy/铒（Holmium，Ho）掺杂是否会产生降低所需切换场的低能量中间态？
• RQ3 纵向和横向自旋霍尔磁阻通道如何反映亚磁转变与 Néel 向量取向？
• RQ4 电输运信号是否能可靠地跟踪掺杂 RFeO3 的磁相边界？

主要发现

• Dy 替代稳定了双自旋重新定向路径，形成低能量中间态。
• 该中间态在低磁场下可被调控进入弱铁磁态。
• 转变的临界场随温度升高而降低。
• 纵向和横向自旋霍尔磁阻通道均显示出清晰的亚磁转变信号。
• 横向通道揭示了 Néel 向量投影到自旋累积方向所带来的额外低场特征。
• 电输运与磁性确定的相边界相关，表明对低能量转变具有纯电学访问能力。