TY - JOUR
T1 - Surface morphology, magnetism and chemical state of Fe coverage on MoS 2 substrate
AU - Hsu, Hung Chang
AU - Wu, Chii Bin
AU - Hsu, Kai Lin
AU - Chang, Po Chun
AU - Fu, Tsu Yi
AU - Mudinepalli, Venkata Ramana
AU - Lin, Wen Chin
N1 - Funding Information:
The authors acknowledge Professor Wang-Chi Vincent Yeh for valuable discussion and technical support. The XPS spectra were taken at the Nanotechnology Research Center, National Dong Hwa University, Hualien, Taiwan. This work was financially sponsored by Ministry of Science and Technology, Taiwan under Grant Nos. NSC 102-2923-M-003-002-MY3 , NSC 102-2112-M-003-003-MY3 and NSC 102-2112-M-033-004-MY3 .
Publisher Copyright:
© 2015 Elsevier B.V. All rights reserved.
PY - 2015/12/1
Y1 - 2015/12/1
N2 - The surface morphology, magnetism and chemical state of Fe coverage on the surface of molybdenum disulfide (MoS 2 ) were investigated using scanning tunneling microscopy, magneto-optical Kerr effect, and depth-profiling X-ray photoemission spectroscopy (XPS). Fe deposition on the MoS 2 substrate resulted in a nanoparticle array with the particle size ranged few nanometers (∼3±1 nm). For low-coverage Fe deposition <6 ML, nanoparticles were well-separated and long-range magnetic ordering was absent at room temperature. When the Fe coverage was increased, in-plane magnetic anisotropy was observed and the magnetic coercivity increased monotonically. The depth-profiling XPS showed the presence of a pure Fe state without observable chemical shift at the Fe/MoS 2 interface. The XPS measurement of Pd/2 ML Fe/MoS 2 also confirmed the dominance of the pure Fe state at the interface. The increase in Fe coverage changed the morphology from a nanoparticle array to a continuous coverage, leading to the onset of the ferromagnetic ordering and the transition from continuous surface oxidation to a bilayer structure.
AB - The surface morphology, magnetism and chemical state of Fe coverage on the surface of molybdenum disulfide (MoS 2 ) were investigated using scanning tunneling microscopy, magneto-optical Kerr effect, and depth-profiling X-ray photoemission spectroscopy (XPS). Fe deposition on the MoS 2 substrate resulted in a nanoparticle array with the particle size ranged few nanometers (∼3±1 nm). For low-coverage Fe deposition <6 ML, nanoparticles were well-separated and long-range magnetic ordering was absent at room temperature. When the Fe coverage was increased, in-plane magnetic anisotropy was observed and the magnetic coercivity increased monotonically. The depth-profiling XPS showed the presence of a pure Fe state without observable chemical shift at the Fe/MoS 2 interface. The XPS measurement of Pd/2 ML Fe/MoS 2 also confirmed the dominance of the pure Fe state at the interface. The increase in Fe coverage changed the morphology from a nanoparticle array to a continuous coverage, leading to the onset of the ferromagnetic ordering and the transition from continuous surface oxidation to a bilayer structure.
KW - Surface magnetism
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U2 - 10.1016/j.apsusc.2015.09.079
DO - 10.1016/j.apsusc.2015.09.079
M3 - Article
AN - SCOPUS:84949818107
VL - 357
SP - 551
EP - 557
JO - Applied Surface Science
JF - Applied Surface Science
SN - 0169-4332
ER -