title: An unconventional method for measuring the Tc L3-edge of technetium compounds.
abstract: Tc L3-edge XANES spectra have been collected on powder samples of SrTcO3 (octahedral Tc(4+)) and NH4TcO4 (tetrahedral Tc(7+)) immobilized in an epoxy resin. Features in the Tc L3-edge XANES spectra are compared with the pre-edge feature of the Tc K-edge as well as other 4d transition metal L3-edges. Evidence of crystal field splitting is obvious in the Tc L3-edge, which is sensitive to the coordination number and oxidation state of the Tc cation. The Tc L3 absorption edge energy difference between SrTcO3 (Tc(4+)) and NH4TcO4 (Tc(7+)) shows that the energy shift at the Tc L3-edge is an effective tool for studying changes in the oxidation states of technetium compounds. The Tc L3-edge spectra are compared with those obtained from Mo and Ru oxide standards with various oxidation states and coordination environments. Most importantly, fitting the Tc L3-edge to component peaks can provide direct evidence of crystal field splitting that cannot be obtained from the Tc K-edge.
authors.affiliation: School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Peter E R
authors.initials: PE
authors.lastname: Blanchard
authors.affiliation: School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Emily
authors.initials: E
authors.lastname: Reynolds
authors.affiliation: School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Brendan J
authors.initials: BJ
authors.lastname: Kennedy
authors.affiliation: School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Chris D
authors.initials: CD
authors.lastname: Ling
authors.affiliation: Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia.
authors.forename: Zhaoming
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2234, Australia.
authors.forename: Gordon
authors.initials: G
authors.lastname: Thorogood
authors.affiliation: Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia.
authors.forename: Bruce C C
authors.initials: BC
authors.lastname: Cowie
authors.affiliation: Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia.
authors.forename: Lars
authors.initials: L
authors.lastname: Thomsen
keywords: Tc L3-edge; XANES; crystal field splitting; radioactive materials; technetium oxides