Open AccessNanometre imaging of Fe3GeTe2 ferromagnetic domain walls
Author(s) -
David G. Hopkinson,
Takahiko Seki,
Nick Clark,
Runze Chen,
Yichao Zou,
Akihiko Kimura,
Roman Gorbachev,
Thomas Thomson,
Naoya Shibata,
Sarah J. Haigh
Publication year - 2021
Publication title -
nanotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.926
H-Index - 203
eISSN - 1361-6528
pISSN - 0957-4484
DOI - 10.1088/1361-6528/abe32b
Subject(s) - materials science , ferromagnetism , condensed matter physics , high resolution transmission electron microscopy , curie temperature , transmission electron microscopy , crystal (programming language) , nanometre , phase (matter) , crystallography , nanotechnology , physics , chemistry , composite material , quantum mechanics , computer science , programming language
Fe 3 GeTe 2 is a layered crystal which has recently been shown to maintain its itinerant ferromagnetic properties even when atomically thin. Here, differential phase contrast scanning transmission electron microscopy is used to investigate the domain structure in a Fe 3 GeTe 2 cross-sectional lamella at temperatures ranging from 95 to 250 K and at nanometre spatial resolution. Below the experimentally determined Curie temperature ( T C ) of 191 K, stripe domains magnetised along 〈0001〉, bounded with 180 ◦ Bloch type domain walls, are observed, transitioning to mixed Bloch−Néel type where the cross-sectional thickness is reduced below 50 nm. When warming towards T C , these domains undergo slight restructuring towards uniform size, before abruptly fading at T C . Localised loss of ferromagnetic order is seen over time, hypothesised to be a frustration of ferromagnetic order from ambient oxidation and basal cracking, which could enable selective modification of the magnetic properties for device applications.