Deduction of the chemical state and the electronic structure of Nd{sub 2}Fe{sub 14}B compound from X-ray photoelectron spectroscopy core-level and valence-band spectra

Journal Article · Tue Oct 28 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4900732· OSTI ID:22308171

Wang, Jing; Liang, Le ^[1]; Zhang, Lanting ^[1]; Sun, Limin ^[2]; Hirano, Shinichi ^[3]

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1. School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)
2. Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai 200240 (China)
3. Hirano Institute for Materials Innovation, Shanghai Jiao Tong University, Shanghai 200240 (China)

Characterization of chemical state and electronic structure of the technologically important Nd{sub 2}Fe{sub 14}B compound is attractive for understanding the physical nature of its excellent magnetic properties. X-ray photoelectron spectroscopy (XPS) study of such rare-earth compound is important and also challenging due to the easy oxidation of surface and small photoelectron cross-sections of rare-earth 4f electrons and B 2p electrons, etc. Here, we reported an investigation based on XPS spectra of Nd{sub 2}Fe{sub 14}B compound as a function of Ar ion sputtering time. The chemical state of Fe and that of B in Nd{sub 2}Fe{sub 14}B compound can be clearly determined to be 0 and −3, respectively. The Nd in Nd{sub 2}Fe{sub 14}B compound is found to have the chemical state of close to +3 instead of +3 as compared with the Nd in Nd{sub 2}O{sub 3}. In addition, by comparing the valence-band spectrum of Nd{sub 2}Fe{sub 14}B compound to that of the pure Fe, the contributions from Nd, Fe, and B to the valence-band structure of Nd{sub 2}Fe{sub 14}B compound is made more clear. The B 2p states and B 2s states are identified to be at ∼11.2 eV and ∼24.6 eV, respectively, which is reported for the first time. The contribution from Nd 4f states can be identified both in XPS core-level spectrum and XPS valence-band spectrum. Although Nd 4f states partially hybridize with Fe 3d states, Nd 4f states are mainly localized in Nd{sub 2}Fe{sub 14}B compound.

• OSTI ID: 22308171
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 16; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BORON COMPOUNDS
CHEMICAL STATE
CROSS SECTIONS
ELECTRONIC STRUCTURE
EV RANGE
IRON COMPOUNDS
MAGNETIC PROPERTIES
NEODYMIUM COMPOUNDS
NEODYMIUM OXIDES
OXIDATION
RARE EARTHS
SPECTRA
SPUTTERING
SURFACES
TERNARY ALLOY SYSTEMS
X-RAY PHOTOELECTRON SPECTROSCOPY