Itinerant ferromagnetism and intrinsic anomalous Hall effect in amorphous iron-germanium

D. S. Bouma; Z. Chen; B. Zhang; F. Bruni; M. E. Flatte; A. Ceballos; R. Streubel; L-W Wang; R. Q. Wu; F. Hellman

doi:10.1103/PhysRevB.101.014402

Back

Itinerant ferromagnetism and intrinsic anomalous Hall effect in amorphous iron-germanium

Journal article

Open access

Peer reviewed

Itinerant ferromagnetism and intrinsic anomalous Hall effect in amorphous iron-germanium

D. S. Bouma, Z. Chen, B. Zhang, F. Bruni, M. E. Flatte, A. Ceballos, R. Streubel, L-W Wang, R. Q. Wu and F. Hellman

Physical review. B, Vol.101(1), p.1

01/02/2020

DOI: 10.1103/PhysRevB.101.014402

Files and links (1)

url

https://research.tue.nl/en/publications/1cd81545-2e63-4107-8783-3c0643fba25eView

Open Access

Abstract

The amorphous iron-germanium system (a-FexGe1-x) lacks long-range structural order and hence lacks a meaningful Brillouin zone. The magnetization of a-FexGe1-x is well explained by the Stoner model for Fe concentrations x above the onset of magnetic order around x = 0.4, indicating that the local order of the amorphous structure preserves the spin-split density of states of the Fe-3d states sufficiently to polarize the electronic structure despite k being a bad quantum number. Measurements reveal an enhanced anomalous Hall resistivity rho(AH)(xy) relative to crystalline FeGe; this rho(AH)(xy) is compared to density-functional theory calculations of the anomalous Hall conductivity to resolve its underlying mechanisms. The intrinsic mechanism, typically understood as the Berry curvature integrated over occupied k states but shown here to be equivalent to the density of curvature integrated over occupied energies in aperiodic materials, dominates the anomalous Hall conductivity of a-FexGe1-x (0.38 <= x <= 0.61). The density of curvature is the sum of spin-orbit correlations of local orbital states and can hence be calculated with no reference to k space. This result and the accompanying Stoner-like model for the intrinsic anomalous Hall conductivity establish a unified understanding of the underlying physics of the anomalous Hall effect in both crystalline and disordered systems.

Materials Science

Physical Sciences

Physics

Technology

Materials Science, Multidisciplinary

Physics, Applied

Physics, Condensed Matter

Science & Technology

Details

Title: Subtitle: Itinerant ferromagnetism and intrinsic anomalous Hall effect in amorphous iron-germanium
Creators: D. S. Bouma - Materials Sciences (United States)
Z. Chen - Materials Sciences (United States)
B. Zhang - Fudan University
F. Bruni - University of California, Berkeley
M. E. Flatte - Eindhoven University of Technology
A. Ceballos - Lawrence Livermore National Laboratory
R. Streubel - Materials Sciences (United States)
L-W Wang - Materials Sciences (United States)
R. Q. Wu - University of California, Irvine
F. Hellman - Materials Sciences (United States)
Resource Type: Journal article
Publication Details: Physical review. B, Vol.101(1), p.1
DOI: 10.1103/PhysRevB.101.014402
ISSN: 2469-9950
eISSN: 2469-9969
Publisher: Amer Physical Soc
Number of pages: 10
Grant note: DE-FG02-05-ER46237 / DOE-BES; United States Department of Energy (DOE) 2015CB921400 / Basic Research Program of China; National Basic Research Program of China DMR-1420451 / Center for Emergent Materials, an NSF MRSEC; National Science Foundation (NSF) DE-AC02-05-CH11231 / US Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division; United States Department of Energy (DOE)
Language: English
Date published: 01/02/2020
Academic Unit: Electrical and Computer Engineering; Physics and Astronomy
Record Identifier: 9984428840202771

Metrics

14 Record Views

20 Times Cited - Web of Science

See more details