Photon Factory Activity Report 2004 #22 Part B (2005)
Electronic Structure of Condensed Matter

NE1/2003G162

Electronic states of Cu-3d electrons in concentrated amorphous Gd-Cu alloys
Kazuo YANO*, Yoshikazu YANAKA1, Ikuo NAKAI2, Atsushi FUKUOKA2, Shinji YAMADA2,Hideki TANAKA2, Fumiki KITABATAKE2, Hiroshi SAKURAI3, Hiromichi ADACHI4, Hiroshi
KAWATA4
Nihon Univ. Narashino-dai, Funabashi, Chiba 274-8501, JapanRIKEN (Harima), Kouto, Hyougo 679-5143, Japan2
Tottori University, Kozancho-minami, Tottori, 680-8552, Japan
3
Gunma University, Kiryu, Gunma, 376-8515, Japan
1KEK-PF, Tsukuba, Ibaraki 305-0801, Japan
Introduction
The Cu metal seems to have played sometimes
fascinating and important rolls in solid state physics.
Over 30 years long-term's research of Rare Earth (RE)Transition metal (TM) alloys, the Cu metal has lured theresearchers to use it in order to isolate the magnetic
exchange interaction of RE alone [1]. The magnetic
isolation of RE can provide a clear clue to understanding
the roll of magnetic electrons of RE (4f, 5s, 5d and 6s).
However, these attempts do not seem to have born fruitful
information about the electric states of RE, since thesample in Cu-rich content did not saturate and showedspin-glass like behavior.
In 1994, Tanaka et al. have tried to elucidate theelectronic states of Cu and Gd for Gd60Cu40 amorphousalloy [2, 3] by means of magnetic Compton profile(MCP) method [4] and have found that the magnetic
moment of the sample was described dominantly by thatof 4f electrons of Gd and that the contribution of spinpolarization of s, p-like electrons was more suppressedthan that of pure Gd metal.
In this report, for the Gd-Cu samples in much richer
content of Gd, we examine mainly the effects of strong
molecular field from Gd upon Cu-3d electrons employing
the MCP measurement.
Experimental
The amorphous alloys of GdXCu100-X (X=67, 70 at%)were quenched from the melt employing a single roller
system. The MCP measurements were carried out at theAR-NE1 beamline. Circularly polarized X-rays emitted
from an elliptical multi-pole wiggler were monochromatized and focused on the sample by a single channelcut bent Si crystal. The energy of incident X-rays weretuned to be 135 keV in order to avoid the effects of somekinds of fluorescence and to obtain a good quality of
MCP signals. The sample was cooled by a closed- typerefrigerator and the temperature of the sample was held tobe 10K and 110K. The magnetic field applied on thesample was 1 Tesla and partly 2 Tesla for 110K, which
are large enough to saturate the sample. The Curie
temperature of the sample was about 145K.

Results and Discussion
Figure 1 shows the experimentally obtained MCP ofamorphous Gd67Cu33 alloy at 10K under the magnetic fieldof 1 Tesla, together with the calculation result. The open
circles are the experimental results and the solid line isthe calculated MCP of atomic 4f electrons of Gd
employing the relativistic Hartree-Fock method [5]. The
most parts of experimental results of MCP (PZ>2.5) canbe described by the calculated 4f electrons of Gd and thisresult shows that the 3d electrons of Cu does notcontribute to the magnetic moment of the sample and aremagnetically inactive.

Fig. 1. Magnetic Compton Profile of Gd67Cu33 amorphous all
The open circles are the experimental results and the solid lin
the calculated result for 4f electrons of Gd.
References[1] N. Heiman and K.Lee, A. I. P. Conf. Proc. 29, 319(1976).
[2] Y. Tanaka et al., Photon Factory, Activity report, #13,370 (1995). (Grant No. 94G-356)[3] K. Yano, Y. Tanaka and E. Kita, J. Magn. Magn.
Mater. 177-181, 132 (1997)[4] N. Sakai, Mat. Sci. Forum 105-110, 431 (1992).
[5] F. Biggs et al., Atomic Data and Nuclear Data
Tables 16, 201 (1975)* kyano@phys.ge.cst.nihon-u.ac.jp

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