Conduction-electron screening in the bulk and at low-index surfaces of Ta metal

Journal Article · Sat Apr 15 04:00:00 EDT 1995 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.51.11012· OSTI ID:44623

Riffe, D M ^[1]; Hale, W; Kim, B; Erskine, J L ^[2]

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1. Department of Physics, Utah State University, Logan, Utah 84322-4415 (United States)
2. Department of Physics, University of Texas, Austin, Texas 78712 (United States)

High-resolution core-level photoemission spectra from Ta(100) have been measured. The well-resolved peak from the first atomic layer allows a separate assessment of bulk and surface-layer screening responses: singularity indices {alpha}{sub {ital B}}=0.10{plus_minus}0.01 and {alpha}{sub 100}=0.205{plus_minus}0.025, respectively, are obtained. The measured surface-atom lifetime broadening of 70{plus_minus}20 meV (compared to 37{plus_minus}5 meV in the bulk) is consistent with published Auger--photoemission coincidence measurements. The result for the bulk singularity index has been applied in the analysis of previous data in order to extract the screening response in the first atomic layer of Ta(111) ({alpha}{sub 111}=0.16{plus_minus}0.01) and Ta(110) ({alpha}{sub 110}=0.150{plus_minus}0.015). The trend in surface {alpha}`s implies an increasingly atomic character for the surface-layer atoms as one proceeds from Ta(110) to Ta(111) to Ta(100).

• OSTI ID: 44623
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 16 Vol. 51; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ELECTRONIC STRUCTURE
PHOTOEMISSION
SINGULARITY
SURFACE PROPERTIES
SYNCHROTRON RADIATION
TANTALUM