Perpendicular Magnetization from Crystallite Boundaries in Polycrystalline Antiferromagnetic γ-FeMn
Abstract
Single-crystalline noncollinear antiferromagnets, such as Mn3Sn, are actively explored as memory media, but they generally require high-temperature growth that is incompatible with industrial-scale device fabrication. Here, we show that polycrystalline films of antiferromagnetic γ-FeMn, grown at room temperature, develop a perpendicular magnetization and an anomalous Hall effect, opening an industrially compatible route to antiferromagnetic memory. While conventional noncollinear antiferromagnets demand near-perfect crystal order, γ-FeMn films derive their memory-enabling properties from crystal defects, particularly boundaries separating nanoscale crystallites. When the crystallite size D falls below ≈ 30 nm, a field-switchable magnetization emerges and increases with the boundary density ∝ 1/D. This magnetization is accompanied by a room-temperature anomalous Hall conductivity exceeding 10 S/cm, comparable to that of single-crystalline Mn3Sn. Our systematic experimental results, including scanning magnetometry, indicate uncompensated spin moments in the boundaries coupled to the compensated antiferromagnetism within the crystallites. We further find that the perpendicular easy axis of the magnetization is stabilized by residual strain within the γ-FeMn film. Our findings in manufacturing-friendly polycrystalline γ-FeMn redefine crystal defects as enablers, rather than impediments, for scalable antiferromagnetic memory.
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BibTeX
@misc{maizel2026perpendicular,
title = {{Perpendicular Magnetization from Crystallite Boundaries in Polycrystalline Antiferromagnetic $γ$-FeMn}},
author = {Rachel E. Maizel and Sachli Abdizadeh and Ali Almahmoud and Omolara A. Bakare and Galen T. Street and Hanu Arava and Sauviz P. Alaei and Sanyum Channa and Daisy A. O'Mahoney and Rishav Khatiwada and Jing Zhao and Charis Horn and Evan Stocker and Benjamin Kostroun and Emilio Corrales and Christoph Klewe and Alpha T. N'Diaye and Yuri Suzuki and Jean J. Heremans and Frederick M. Michel and Mitsuhiro Murayama and Vsevolod M. Ivanov and Satoru Emori},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.29614},
eprint = {2610.29614},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.29614},
}
RIS
TY - UNPB
TI - Perpendicular Magnetization from Crystallite Boundaries in Polycrystalline Antiferromagnetic γ-FeMn
AU - Rachel E. Maizel
AU - Sachli Abdizadeh
AU - Ali Almahmoud
AU - Omolara A. Bakare
AU - Galen T. Street
AU - Hanu Arava
AU - Sauviz P. Alaei
AU - Sanyum Channa
AU - Daisy A. O'Mahoney
AU - Rishav Khatiwada
AU - Jing Zhao
AU - Charis Horn
AU - Evan Stocker
AU - Benjamin Kostroun
AU - Emilio Corrales
AU - Christoph Klewe
AU - Alpha T. N'Diaye
AU - Yuri Suzuki
AU - Jean J. Heremans
AU - Frederick M. Michel
AU - Mitsuhiro Murayama
AU - Vsevolod M. Ivanov
AU - Satoru Emori
PY - 2026
DA - 2026/10/21
PB - arXiv
DO - 10.48550/arxiv.2610.29614
UR - https://arxiv.org/abs/2610.29614
AB - Single-crystalline noncollinear antiferromagnets, such as Mn_3Sn, are actively explored as memory media, but they generally require high-temperature growth that is incompatible with industrial-scale device fabrication. Here, we show that polycrystalline films of antiferromagnetic γ-FeMn, grown at room temperature, develop a perpendicular magnetization and an anomalous Hall effect, opening an industrially compatible route to antiferromagnetic memory. While conventional noncollinear antiferromagnets demand near-perfect crystal order, γ-FeMn films derive their memory-enabling properties from crystal defects, particularly boundaries separating nanoscale crystallites. When the crystallite size D falls below ≈ 30 nm, a field-switchable magnetization emerges and increases with the boundary density ∝ 1/D. This magnetization is accompanied by a room-temperature anomalous Hall conductivity exceeding 10 S/cm, comparable to that of single-crystalline Mn_3Sn. Our systematic experimental results, including scanning magnetometry, indicate uncompensated spin moments in the boundaries coupled to the compensated antiferromagnetism within the crystallites. We further find that the perpendicular easy axis of the magnetization is stabilized by residual strain within the γ-FeMn film. Our findings in manufacturing-friendly polycrystalline γ-FeMn redefine crystal defects as enablers, rather than impediments, for scalable antiferromagnetic memory.
ER -