Relativistic tight-binding calculations of x-ray absorption and magnetic circular dichroism at the L sub 2 and L sub 3 edges of nickel and iron

Journal Article · Wed Jul 01 00:00:00 EDT 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.46.1023· OSTI ID:5004683

Smith, N V; Chen, C T; Sette, F; Mattheiss, L F ^[1]

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1. AT T Bell Laboratories, Murray Hill, New Jersey 07974 (United States)

The soft-x-ray absorption and magnetic circular dichroism (MCD) cross sections at the {ital L}{sub 2} and {ital L}{sub 3} core-level edges of Ni and Fe have been calculated using a one-electron tight-binding band-structure approach. The tight-binding scheme is taken from the work of Papaconstantopoulos, supplemented with the inclusion of spin-orbit coupling in the {ital d} bands and fully relativistic dipole selection rules. In Ni, a fit to the various {ital L}{sub 2} and {ital L}{sub 3} intensity ratios can be achieved, but only with values of the {ital d}-band spin-orbit parameter {xi} and exchange parameter {Delta}{sub ex} at variance with the ground-state band-structure values. For Fe, there is no plausible value of {xi} capable of explaining the intensity ratios; also, the predicted substructure within the {ital L}{sub 2} and {ital L}{sub 3} white lines is not seen in experiment. These failures of the one-electron approach are qualitatively consistent with expected many-body electronic rearrangements associated with core-hole creation. Some discussion is offered on sum rules and on orbital versus spin magnetic moments.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 5004683
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 46:2; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
IRON
ABSORPTION SPECTRA
NICKEL
MAGNETIC CIRCULAR DICHROISM
MAGNETIC MOMENTS
NUMERICAL ANALYSIS
RELATIVISTIC RANGE
SOFT X RADIATION
SUM RULES
DICHROISM
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY RANGE
EQUATIONS
IONIZING RADIATIONS
MATHEMATICS
METALS
RADIATIONS
SPECTRA
TRANSITION ELEMENTS
X RADIATION
360104* - Metals & Alloys- Physical Properties