[Paper Review] 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 materials0 citations

TL;DR

The paper shows an electrically accessible metamagnetic transition in a doped antiferromagnetic insulator Ho0.5Dy0.5FeO3, by stabilizing a low-energy intermediate magnetic state that allows switching at low magnetic fields, with spin Hall magnetoresistance signaling the transition.

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.

Motivation & Objective

• Motivate low-power spintronic control in insulating antiferromagnets by accessing low-energy magnetic transitions.
• Investigate how rare-earth site engineering (Dy/Ho mix) modifies spin-reorientation pathways in RFeO3.
• Demonstrate a doping-induced intermediate antiferromagnetic state with reduced energy barrier that enables metamagnetic switching.
• Correlate electrical transport signals with magnetically defined phase boundaries to establish electrical access to magnetic transitions.

Proposed method

• Synthesize Ho0.5Dy0.5FeO3 with targeted rare-earth-site composition.
• Characterize spin-reorientation sequences from DyFeO3 and HoFeO3 to identify dual-pathway behavior.
• Apply low magnetic fields to drive transitions and monitor via longitudinal and transverse spin Hall magnetoresistance.
• Analyze how the intermediate low-energy state lowers the energy barrier for metamagnetic switching.
• Correlate electrical transport measurements with magnetically determined phase boundaries to validate electrical control of magnetic states.

Experimental results

Research questions

• RQ1 Can rare-earth site engineering enable an electrically accessible metamagnetic transition in insulating antiferromagnets?
• RQ2 Does doping with Dy/Holmium create a low-energy intermediate state that reduces the required switching field?
• RQ3 How do longitudinal and transverse spin Hall magnetoresistance channels reflect metamagnetic transitions and Neel vector orientation?
• RQ4 Can electrical transport signals reliably track magnetic phase boundaries in doped RFeO3?

Key findings

• A dual spin-reorientation pathway stabilized by Dy substitution creates a low-energy intermediate state.
• The intermediate state can be tuned into a weak-ferromagnetic state under low magnetic fields.
• Critical field for the transition decreases with increasing temperature.
• Both longitudinal and transverse spin Hall magnetoresistance channels show clear signatures of metamagnetic transitions.
• Transverse channel reveals additional low-field features due to Neel vector projection onto spin-accumulation direction.
• Electrical transport correlates with magnetically determined phase boundaries, indicating purely electrical access to low-energy transitions.