Electronic Structure of B-2p State in AlB2 Single Crystal: Direct Observation of pσ and pπ Density of States

Jin Nakamura; Masamitsu Watanabe; Tamio Oguchi; Sin Ya Nasubida; Eiki Kabasawa; Nobuyoshi Yamada; Kazuhiko Kuroki; Hisashi Yamazaki; Shik Shin; Yuji Umeda; Shin Minakawa; Noriaki Kimura; Haruyoshi Aoki

doi:10.1143/JPSJ.71.408

Electronic Structure of B-2p State in AlB₂ Single Crystal: Direct Observation of pσ and pπ Density of States

Jin Nakamura, Masamitsu Watanabe, Tamio Oguchi, Sin Ya Nasubida, Eiki Kabasawa, Nobuyoshi Yamada, Kazuhiko Kuroki, Hisashi Yamazaki, Shik Shin, Yuji Umeda, Shin Minakawa, Noriaki Kimura, Haruyoshi Aoki

SCI - Physics

Research output: Contribution to journal › Article › peer-review

18 Citations (Scopus)

Abstract

X-ray emission (XES) and absorption (XAS) spectra near the B-K edge were measured on single-crystalline AlB₂ compound which is an isostructural diboride of superconducting MgB₂. The partial density of states (PDOS) of B-2pσ and pπ orbitals were derived from the polarization dependence of XES and XAS spectra. There are considerable amounts of PDOS near the Fermi energy in AlB₂ similarly to that in MgB ₂, but there are almost no PDOS in pσ orbitals of AlB ₂ near the Fermi energy, i.e., a pseudo-gap in pσ state and a broad metallic state in pπ state are observed. The present result indirectly supports scenarios that the pσ holes play an important role in the occurrence of superconductivity in MgB₂. The overall features of PDOS were found to be in good agreement with the result of band calculation of AlB₂, but a small discrepancy in the Fermi energy is observed, which is attributed to the Al vacancy in the compounds, i.e., the estimated concentration is Al_0.93B₂.

Original language	English
Pages (from-to)	408-410
Number of pages	3
Journal	Journal of the Physical Society of Japan
Volume	71
Issue number	2
DOIs	https://doi.org/10.1143/JPSJ.71.408
Publication status	Published - 2002 Feb

Keywords

AlB2
MgB2
Partial density of state
Pσ and pπ orbitals
Single crystal
X-ray emission and absorption spectroscopy

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10.1143/JPSJ.71.408

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Nakamura, J., Watanabe, M., Oguchi, T., Nasubida, S. Y., Kabasawa, E., Yamada, N., Kuroki, K., Yamazaki, H., Shin, S., Umeda, Y., Minakawa, S., Kimura, N., & Aoki, H. (2002). Electronic Structure of B-2p State in AlB₂ Single Crystal: Direct Observation of pσ and pπ Density of States. Journal of the Physical Society of Japan, 71(2), 408-410. https://doi.org/10.1143/JPSJ.71.408

@article{d27bcf266aa2447786a999c0503f573d,

title = "Electronic Structure of B-2p State in AlB2 Single Crystal: Direct Observation of pσ and pπ Density of States",

abstract = "X-ray emission (XES) and absorption (XAS) spectra near the B-K edge were measured on single-crystalline AlB2 compound which is an isostructural diboride of superconducting MgB2. The partial density of states (PDOS) of B-2pσ and pπ orbitals were derived from the polarization dependence of XES and XAS spectra. There are considerable amounts of PDOS near the Fermi energy in AlB2 similarly to that in MgB 2, but there are almost no PDOS in pσ orbitals of AlB 2 near the Fermi energy, i.e., a pseudo-gap in pσ state and a broad metallic state in pπ state are observed. The present result indirectly supports scenarios that the pσ holes play an important role in the occurrence of superconductivity in MgB2. The overall features of PDOS were found to be in good agreement with the result of band calculation of AlB2, but a small discrepancy in the Fermi energy is observed, which is attributed to the Al vacancy in the compounds, i.e., the estimated concentration is Al0.93B2.",

keywords = "AlB2, MgB2, Partial density of state, Pσ and pπ orbitals, Single crystal, X-ray emission and absorption spectroscopy",

author = "Jin Nakamura and Masamitsu Watanabe and Tamio Oguchi and Nasubida, {Sin Ya} and Eiki Kabasawa and Nobuyoshi Yamada and Kazuhiko Kuroki and Hisashi Yamazaki and Shik Shin and Yuji Umeda and Shin Minakawa and Noriaki Kimura and Haruyoshi Aoki",

year = "2002",

month = feb,

doi = "10.1143/JPSJ.71.408",

language = "English",

volume = "71",

pages = "408--410",

journal = "Journal of the Physical Society of Japan",

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publisher = "The Physical Society of Japan",

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}

Nakamura, J, Watanabe, M, Oguchi, T, Nasubida, SY, Kabasawa, E, Yamada, N, Kuroki, K, Yamazaki, H, Shin, S, Umeda, Y, Minakawa, S, Kimura, N & Aoki, H 2002, 'Electronic Structure of B-2p State in AlB₂ Single Crystal: Direct Observation of pσ and pπ Density of States', Journal of the Physical Society of Japan, vol. 71, no. 2, pp. 408-410. https://doi.org/10.1143/JPSJ.71.408

TY - JOUR

T1 - Electronic Structure of B-2p State in AlB2 Single Crystal

T2 - Direct Observation of pσ and pπ Density of States

AU - Nakamura, Jin

AU - Watanabe, Masamitsu

AU - Oguchi, Tamio

AU - Nasubida, Sin Ya

AU - Kabasawa, Eiki

AU - Yamada, Nobuyoshi

AU - Kuroki, Kazuhiko

AU - Yamazaki, Hisashi

AU - Shin, Shik

AU - Umeda, Yuji

AU - Minakawa, Shin

AU - Kimura, Noriaki

AU - Aoki, Haruyoshi

PY - 2002/2

Y1 - 2002/2

N2 - X-ray emission (XES) and absorption (XAS) spectra near the B-K edge were measured on single-crystalline AlB2 compound which is an isostructural diboride of superconducting MgB2. The partial density of states (PDOS) of B-2pσ and pπ orbitals were derived from the polarization dependence of XES and XAS spectra. There are considerable amounts of PDOS near the Fermi energy in AlB2 similarly to that in MgB 2, but there are almost no PDOS in pσ orbitals of AlB 2 near the Fermi energy, i.e., a pseudo-gap in pσ state and a broad metallic state in pπ state are observed. The present result indirectly supports scenarios that the pσ holes play an important role in the occurrence of superconductivity in MgB2. The overall features of PDOS were found to be in good agreement with the result of band calculation of AlB2, but a small discrepancy in the Fermi energy is observed, which is attributed to the Al vacancy in the compounds, i.e., the estimated concentration is Al0.93B2.

AB - X-ray emission (XES) and absorption (XAS) spectra near the B-K edge were measured on single-crystalline AlB2 compound which is an isostructural diboride of superconducting MgB2. The partial density of states (PDOS) of B-2pσ and pπ orbitals were derived from the polarization dependence of XES and XAS spectra. There are considerable amounts of PDOS near the Fermi energy in AlB2 similarly to that in MgB 2, but there are almost no PDOS in pσ orbitals of AlB 2 near the Fermi energy, i.e., a pseudo-gap in pσ state and a broad metallic state in pπ state are observed. The present result indirectly supports scenarios that the pσ holes play an important role in the occurrence of superconductivity in MgB2. The overall features of PDOS were found to be in good agreement with the result of band calculation of AlB2, but a small discrepancy in the Fermi energy is observed, which is attributed to the Al vacancy in the compounds, i.e., the estimated concentration is Al0.93B2.

KW - AlB2

KW - MgB2

KW - Partial density of state

KW - Pσ and pπ orbitals

KW - Single crystal

KW - X-ray emission and absorption spectroscopy

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DO - 10.1143/JPSJ.71.408

M3 - Article

AN - SCOPUS:0036246692

SN - 0031-9015

VL - 71

SP - 408

EP - 410

JO - Journal of the Physical Society of Japan

JF - Journal of the Physical Society of Japan

IS - 2

ER -

Electronic Structure of B-2p State in AlB₂ Single Crystal: Direct Observation of pσ and pπ Density of States

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