Electronic structure of YbGa1.15Si0:85 and YbGaxGe2-x probed by resonant x-ray emission and photoelectron spectroscopies

Journal Article · Thu Mar 31 04:00:00 EDT 2011 · Phys. Rev. B

DOI:https://doi.org/10.1103/PhysRevB.83.104525· OSTI ID:1065310

Yamaoka, Hitoshi ^[1]; Jarrige, Ignace ^[2]; Tsujii, Naohito ^[3]; Imai, Motoharu ^[3]; Lin, Jung-Fu ^[4]; Matsunami, Masaharu ^[5]; Eguchi, Ritsuko ^[6]; Arita, Masashi ^[7]; Shimada, Kenya ^[7]; Namatame, Hirofumi ^[7]; Taniguchi, Masaki ^[7]; Taguchi, Munetaka ^[1]; Senba, Yasunori ^[8]; Ohashi, Haruhiko ^[8]; Hiraoka, Nozomu ^[9]; Ishii, Hirofumi ^[9]; Tsuei, Ku-Ding ^[9]

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1. RIKEN, Hyogo (Japan)
2. Japan Atomic Energy Agency (JAEA), Tokai (Japan)
3. National Inst. for Materials Science (NIMS), Tsukuba (Japan)
4. Univ. of Texas, Austin, TX (United States)
5. Inst. for Molecular Science, Okazaki (Japan)
6. Okayama Univ. (Japan)
7. Hiroshima Univ. (Japan)
8. Japan Synchrotron Research Inst., Hyogo (Japan)
9. National Synchrotron Radiation Research Center, Hsinchu (Taiwan)

We performed an x-ray spectroscopic study combining resonant x-ray emission spectroscopy (RXES) and photoelectron spectroscopy on the superconducting ternary silicide YbGa _1.15 Si _0.85 and nonsuperconducting ternary germanide YbGa_x Ge_2-x (x = 1.0 and 1.1). The Yb valence for all three compounds is found to be about 2.3. In YbGa_1.15 Si_0.85 no temperature dependence of the Yb valence is observed in the RXES spectra in the temperature range of 7–300 K, while the valence shows a drastic increase under pressure from the Yb²⁺ state partially including itinerant electrons to the localized Yb³⁺ state. Differences are observed in the valence-band spectra of the photoelectron spectroscopy between YbGa_1.15 Si_0.85 and YbGa_x Ge_2-x , which may be attributed to the difference of crystal structure. We conclude that both the crystal structure of the planar GaSi layer in YbGa_1.15 Si_0.85 and the resultant electronic structure may have a crucial role in the occurrence of superconductivity.

• Research Organization: Energy Frontier Research Centers (EFRC); Energy Frontier Research in Extreme Environments (EFree)
• Sponsoring Organization: USDOE SC Office of Basic Energy Sciences (SC-22)
• DOE Contract Number: SC0001057
• OSTI ID: 1065310
• Journal Information: Phys. Rev. B, Journal Name: Phys. Rev. B Journal Issue: 10 Vol. 83
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
catalysis (heterogeneous)
charge transport
energy storage (including batteries and capacitors)
hydrogen and fuel cells
materials and chemistry by design
mesostructured materials
phonons
solar (photovoltaic)
superconductivity
synthesis (novel materials)
thermoelectric