Fengyuan Yang (Ohio State University)

Date: Mon. October 13th, 2025, 12:45 pm-1:45 pm
Location: Rockefeller 221 (Foldy Room) & Zoom

Robust Biaxial Anisotropy and Electrical Switching of LaFeO₃ Epitaxial Thin Films

Fengyuan Yang

Department of Physics, The Ohio State University

(Host: Shulei Zhang)

Abstract: Antiferromagnetic (AFM) spintronics has generated considerable interest since the demonstration of electrical switching of AFMs.  AFMs with robust biaxial anisotropy, accessible spin-flop fields, and high Néel temperatures are ideal for AFM spintronics.  Currently, AFM research has been mostly focused on binary AFMs, while the large family of complex oxide AFMs has been much less unexplored. Here, we show the growth of high quality LaFeO₃ epitaxial films down to 1 nm thickness on SrTiO₃(001). Using angular-dependent spin-Hall magnetoresistance (SMR) characterization of Pt/LaFeO₃ bilayers, we observe (1) a robust and easily accessible spin-flop field of 1-3 T, (2) a square-shaped transverse SMR with 90-degree wide plateaus at 2-5 T, indicating a clear biaxial anisotropy, and a saw-tooth-shaped longitudinal SMR with well-defined subtle features; and (3) decreasing magnitudes and sinusoidal shape of SMR at higher fields up to 14 T. The clear biaxial anisotropy persists down to 2-nm LaFeO₃ and AFM ordering is detected in 1-nm LaFeO₃ at 25 K. Our experimental SMR results can be precisely simulated by a macrospin model, which captures all the subtle details [1]. We pattern two Hall bars with the current channel along SrTiO₃ [100] (AFM hard axis) and [110] (easy axis), which show switched shapes of square and saw-tooth SMR between longitudinal and transverse SMR.  Our model accurately explains the shape switching as well as the fine features of these two samples. We also perform electrical switching of the Néel vector between two easy axes, which exhibit clean and reversable switching in Pt/LaFeO₃ bilayers [2]. This work indicates that LaFeO₃ and other AFM perovskites are promising candidates for AFM-based spintronic applications, which will greatly expand the scope of the field of AFM spintronics.

This work was primarily supported by the Department of Energy under Grant No. DE-SC0001304.

References:

1. Lanier, J. Michel, J. Flores, and F. Y. Yang, “Robust Biaxial Anisotropy and Switchable Néel Vectors in LaFeO₃Epitaxial Films,” Nano Lett. 25, 4667 (2025).
2. Lanier, et al. “Electrical Pulse Switching and Imaging of Antiferromagnetic Spins in Perovskite Epitaxial Films,” Submitted.