The near-edge structure in energy-loss spectroscopy: many-electron and magnetic effects in transition metal nitrides and carbides

Anthony Paxton, M. Van Schilfgaarde, M. MacKenzie, A.J. Craven

Research output: Contribution to journalArticle

69 Citations (Scopus)

Abstract

We investigate the ability of the local density approximation (LDA) in density functional theory to predict the near-edge structure in electron energy-loss spectroscopy in the dipole approximation. We include screening of the core hole within the LDA using Slater's transition state theory. We find that anion K-edge threshold energies are systematically overestimated by 4.22 +/- 0.44 eV in twelve transition metal carbides and nitrides in the rock-salt (B1) structure. When we apply this 'universal' many-electron correction to energy-loss spectra calculated within the transition state approximation to LDA, we find quantitative agreement with experiment to within one or two eV for TiC, TiN and VN. We compare our calculations to a simpler approach using a projected Mulliken density which honours the dipole selection rule, in place of the dipole matrix element itself. We find remarkably close agreement between these two approaches. Finally, we show an anomaly in the near-edge structure in CrN to be due to magnetic structure. In particular, we find that the N K edge in fact probes the magnetic moments and alignments of ther sublattice.
Original languageEnglish
Pages (from-to)729-750
Number of pages22
JournalJ. Phys. Cond. Matt.
Volume12
Issue number5
DOIs
Publication statusPublished - 07 Feb 2000

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials

Fingerprint Dive into the research topics of 'The near-edge structure in energy-loss spectroscopy: many-electron and magnetic effects in transition metal nitrides and carbides'. Together they form a unique fingerprint.

  • Cite this