Vanadium K XANES of synthetic olivine: Valence determinations and crystal orientation effects
- UC
Vanadium can exist in a large number of valence states in nature (2+?, 3+, 4+ and 5+) and determinations of V valence is therefore valuable in defining the oxidation states of earth and planetary materials over a large redox range. Synchrotron-based x-ray absorption near edge structure (XANES) spectroscopy is well-suited for measurements of V valence with {approx}micrometer spatial resolution and {approx}ppm elemental sensitivity. Applications of microXANES have been demonstrated for basaltic glasses. Applications to minerals are feasible but complicated by orientation effects (e.g. due to polarization of the synchrotron x-ray beam) and some results for spinel have been reported. Here we report initial results for olivine from laboratory crystallization ex-periments. The goal is to define the valence partition-ing between olivine and melt and quantify the magnitude of orientation effects, the latter tested by measuring grains at a variety of orientations in the same charge.
- Research Organization:
- Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 1008944
- Country of Publication:
- United States
- Language:
- ENGLISH
Similar Records
Oxidation state of vanadium in glass and olivine from terrestrial and Martian basalts: Implications for oxygen fugacity estimates
Micro-XANES measurements on experimental spinels and the oxidation state of vanadium in coexisting spinel and silicate melt