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Title: Local Structure of Transition Elements (V, Cr, Mn, Fe and Zn) in Al2SiO5 Polymorphs

Abstract

We measured XAFS spectra near the Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn K-edges in Al2SiO5 polymorphs to reveal the local structure around these elements in the minerals. XANES spectra show that the valence of Fe and Cr is different depending on the crystal structure and formation environments. The spectra of kyanite, a high pressure mineral, shift to high energy side. The Fe-O bond length of kyanite determined by EXAFS data analyses is the shortest of all samples.

Authors:
; ;  [1];  [2];  [3];  [4]
  1. Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555 (Japan)
  2. Graduate School of Science, Osaka University, Toyonaka 560-0043, (Japan)
  3. Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-850 (Japan)
  4. Faculty of Engineering, Tokushima University, Tokushima 770-8506 (Japan)
Publication Date:
OSTI Identifier:
21054602
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 882; Journal Issue: 1; Conference: XAFS13: 13. international conference on X-ray absorption fine structure, Stanford, CA (United States), 9-14 Jul 2006; Other Information: DOI: 10.1063/1.2644486; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION SPECTRA; ABSORPTION SPECTROSCOPY; ALUMINIUM SILICATES; BOND LENGTHS; CHROMIUM; COPPER; CRYSTAL STRUCTURE; DATA ANALYSIS; FINE STRUCTURE; IRON; MANGANESE; MINERALS; NICKEL; VALENCE; VANADIUM; X-RAY SPECTRA; X-RAY SPECTROSCOPY; ZINC

Citation Formats

Furukawa, Yuki, Yoshiasa, Akira, Nishiyama, Tadao, Arima, Hiroshi, Okube, Maki, and Murai, Kei-ichiro. Local Structure of Transition Elements (V, Cr, Mn, Fe and Zn) in Al2SiO5 Polymorphs. United States: N. p., 2007. Web. doi:10.1063/1.2644486.
Furukawa, Yuki, Yoshiasa, Akira, Nishiyama, Tadao, Arima, Hiroshi, Okube, Maki, & Murai, Kei-ichiro. Local Structure of Transition Elements (V, Cr, Mn, Fe and Zn) in Al2SiO5 Polymorphs. United States. doi:10.1063/1.2644486.
Furukawa, Yuki, Yoshiasa, Akira, Nishiyama, Tadao, Arima, Hiroshi, Okube, Maki, and Murai, Kei-ichiro. Fri . "Local Structure of Transition Elements (V, Cr, Mn, Fe and Zn) in Al2SiO5 Polymorphs". United States. doi:10.1063/1.2644486.
@article{osti_21054602,
title = {Local Structure of Transition Elements (V, Cr, Mn, Fe and Zn) in Al2SiO5 Polymorphs},
author = {Furukawa, Yuki and Yoshiasa, Akira and Nishiyama, Tadao and Arima, Hiroshi and Okube, Maki and Murai, Kei-ichiro},
abstractNote = {We measured XAFS spectra near the Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn K-edges in Al2SiO5 polymorphs to reveal the local structure around these elements in the minerals. XANES spectra show that the valence of Fe and Cr is different depending on the crystal structure and formation environments. The spectra of kyanite, a high pressure mineral, shift to high energy side. The Fe-O bond length of kyanite determined by EXAFS data analyses is the shortest of all samples.},
doi = {10.1063/1.2644486},
journal = {AIP Conference Proceedings},
number = 1,
volume = 882,
place = {United States},
year = {Fri Feb 02 00:00:00 EST 2007},
month = {Fri Feb 02 00:00:00 EST 2007}
}
  • Consistent ab initio calculations (generalized valence bond plus configuration interaction are presented for the 11 molecules MH/sup +/ with M = Ca through Zn. The ground-state symmetry, bond distance, vibration frequency, and bond energy are reported. The character of the wave function is used to analyze the bond energy and to rationalize the ground-state symmetry and spectroscopic properties. Excellent agreement (average error = 3.5 kcal) is found with recent experimental bond energies. 15 references, 2 figures, 3 tables.
  • Local-density-functional calculations have been performed to study the electronic structure and magnetism of 3d transition-metal ions (Cr, Mn, Fe, Co, and Ni) substituting for the Cu ion in La{sub 2{minus}{ital x}}Sr{sub {ital x}}CuO{sub 4}. These systems are simulated by small clusters which are surrounded by over 5000 point charges. It is found that all the substituting ions possess local magnetic moments. Through a systematic comparison we find that the Cu-O system has the smallest {ital p}-{ital d} separation and the largest {ital p}-{ital d} hybridization. The Cu-O system has the smallest local magnetic moment, which can be reduced to zeromore » by hole doping. We also find that removing an electron from these systems further increases the {ital p}-{ital d} hybridization. The crystal-field splittings of these transition-metal oxide systems are found to remain nearly constant at about 0.1 Ry, while the Jahn-Teller splittings vary considerably, depending on the manner in which single-particle levels are filled. Hyperfine fields have been calculated for the Fe ion at both trivalent and divalent states. These calculations are compared with available experimental measurements.« less
  • Vibrationally resolved photoelectron spectra of MC{sub 2}{sup {minus}} (M=Sc, V, Cr, Mn, Fe, and Co) are reported at two detachment photon energies, 532 and 355 nm. All the spectra showed a well resolved vibrational progression in the ground state detachment features. Electron affinities, vibrational frequencies, and information about the low-lying electronic states were obtained for the first row transition metal dicarbide molecules. The measured electron affinities for the MC{sub 2} species show strong metal-dependence with a minimum at VC{sub 2} and a maximum at MnC{sub 2}. The ground state vibrational frequencies were observed to decrease from ScC{sub 2} to amore » minimum in CrC{sub 2} and then increases slightly in MnC{sub 2} and FeC{sub 2}. The trends of the electron affinities and vibrational frequencies for the MC{sub 2} species were found to correlate well with the corresponding monoxides, suggesting that the chemical bonding in M{endash}C{sub 2} is analogous to that in M{endash}O. The M{endash}C{sub 2} bonding was thus interpreted to be quite ionic, and MC{sub 2} can be qualitatively viewed as M{sup 2+}C{sub 2}{sup 2{minus}}, analogous to M{sup 2+}O{sup 2{minus}}. {copyright} {ital 1999 American Institute of Physics.}« less