SPring-8, the large synchrotron radiation facility

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SOL-0000001161

Beamline

BL08W (High Energy Inelastic Scattering)

Scientific keywords

A. Sample category inorganic material metal, alloy, solid-state crystal inelastic scattering Compton scattering polarization (linear) X-ray (> 40 keV) electronic state

Industrial keywords

level 1---Application area mechanics, industrial material, others electronic state X-ray diffraction

Classification

A80.20 metal ・material

Body text

Compton scattering measurement is a unique technique to study electron momentum density distribution. Using this technique, one can measure electronic structure such as the Fermi surface geometry or the number of electrons in orbital states. This technique is used in various experimental conditions because of its insensibility to crystalline imperfections and applicability to bulky samples. The figure shows the electron momentum density of decagonal Al72Ni12Co16. It determined the number of electrons in the free-electron-like and 3d states in the decagonal quasicrystal.

Experimental valence electron Compton profiles of decagonal Al72Ni12Co16.
The solid curve represents the fitted d-electron profile.

[ J. Tamura-Okada, Y. Watanabe, Y. Yokoyama, N. Hiraoka, M. Itou, Y. Sakurai and S. Nanao, Journal of Physics: Condensed Matter 14, L43-L48 (2002), Fig. 1,
©2002 Institute of Physics and IOP Publishing, Ltd. ]

Source of the figure

Original paper/Journal article

Journal title

J-T. Okada et.al, Journal of Physics: Condensed Matter 14 (2002) L43-48

1

Technique

A Compton profile, J(pz), is obtained from an energy spectrum of Compton scattered X-rays on a fixed scattering angle. It provides a twice integrated profile of electron momentum density. The area under the Compton profile is equal to the number of total electrons. A Compton Profile can be decomposed into a few partial profiles with the characteristic shape of a specific electronic state, the area under the partial profile gives the number of electrons associated with that state.

$J(p_z) = \iint \rho (\b{p}) dp_xdp_y$

No figure

4 hour(s)

Instruments

Instrument Purpose Performance
High resolution Compton scattering spectrometer Compton measurement momentum resolution 0.14 atomic unit

References

Document name
J-T, Okada et.al., Journal of Physics: Condensed Matter 14 (2002) L43-48

Related experimental techniques

angle-resolved photoelectronemission spectroscopy
positron annihilation
electron scattering

Questionnaire

The measurement was possible only in SPring-8. Impossible or very difficult in other facilities.
This solution is an application of a main instrument of the beamline.
Similar experiments account for more than 30% of the beamline's subject.

Easy

Middle

Four-nine shifts