6533b86efe1ef96bd12cb615

RESEARCH PRODUCT

New fine structures resolved at the ELNES Ti-L2,3 edge spectra of anatase and rutile: comparison between experiment and calculation.

M. CheynetStephan IrsenSimone PokrantP. Krüger

subject

010302 applied physicsLigand field theoryAnataseMaterials scienceScatteringElectron energy loss spectroscopyAnalytical chemistry02 engineering and technology[CHIM.MATE]Chemical Sciences/Material chemistry021001 nanoscience & nanotechnology01 natural sciencesMolecular physicsAtomic and Molecular Physics and OpticsSpectral lineElectronic Optical and Magnetic Materialslaw.inventionG bandlaw[ CHIM.MATE ] Chemical Sciences/Material chemistry0103 physical sciences0210 nano-technologyElectronic band structureInstrumentationComputingMilieux_MISCELLANEOUSMonochromator

description

Abstract Anatase and rutile Ti- L 2,3 edge spectra were measured in electron energy loss spectroscopy (EELS) using a transmission electron microscope (TEM) coupled to a CEOS Cs-probe corrector, an omega-type monochromator and an in-column omega-type energy filter fully corrected for 2nd order aberrations. Thanks to the high energy resolution, high electron probe current and high stability achieved under this instrumental configuration, new fine structures, never reported before, were resolved at the L 3 band of both rutile and anatase. The data suggest that new peaks also exist in the L 2 e g band. The experimental spectra are compared with multichannel multiple scattering (MMS) calculations. Good agreement is found for number, energy position and intensity of the newly resolved spectral features. Up to now, the L 3 e g band splitting could not be well described by theory not even through the crystal field multiplet approach. We show that the L 3 e g band splitting is due to long range band structure effects, contrary to the usual interpretations in terms of local ligand field or near-neighbour hybridization effects.

https://hal.archives-ouvertes.fr/hal-00591217