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Titanium incorporation and Ti-VI(3+)-Ti-IV(4+) charge transfer in synthetic diopside

Skogby, Henrik ; Halenius, Ulf ; Kristiansson, Per LU and Ohashi, Haruo (2006) In American Mineralogist 91(11-12). p.1794-1801
Abstract
A series of Ti-doped diopside samples synthesized by fluxgrowth methods under reducing conditions were investigated by microanalytical methods and optical absorption spectroscopy, to assess Ti incorporation mechanisms, valence states, and related electronic transitions. Chemical characterization show that Ti occurs both in the tri-and tetravalent states, with Ti4+ preferentially ordered to the tetrahedral position whereas Till is restricted to the M1 position. Charge-balance is maintained by incorporation of Na and minor B, stemming from the flux compound. Polarized optical absorption spectra reveal three major absorption features. Two relatively narrow bands centered at 18 500 and 15 700 cm(-1), mainly polarized in the crystallographic... (More)
A series of Ti-doped diopside samples synthesized by fluxgrowth methods under reducing conditions were investigated by microanalytical methods and optical absorption spectroscopy, to assess Ti incorporation mechanisms, valence states, and related electronic transitions. Chemical characterization show that Ti occurs both in the tri-and tetravalent states, with Ti4+ preferentially ordered to the tetrahedral position whereas Till is restricted to the M1 position. Charge-balance is maintained by incorporation of Na and minor B, stemming from the flux compound. Polarized optical absorption spectra reveal three major absorption features. Two relatively narrow bands centered at 18 500 and 15 700 cm(-1), mainly polarized in the crystallographic c-direction, display absorbance values that correlate with the calculated Ti3+ (M1) concentration, and are assigned to spin-allowed d-d transitions in Till. A broader band centered around 24 500 cm-1 displays absorbance values that are well correlated with the product of Ti-VI(3+) and Ti-IV(4+). Based on the spectral characteristics of this band, including a strong polarization in the crystallographic b-direction, we assign this band to an Ti-M1(3+)-Ti-T(4+) intervalence charge transfer process. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
minor elements, major and, pyroxene, optical spectroscopy, crystal synthesis, diopside, Ti in pyroxene, order-disorder
in
American Mineralogist
volume
91
issue
11-12
pages
1794 - 1801
publisher
Mineralogical Society of America
external identifiers
  • wos:000242318100008
  • scopus:33845249757
ISSN
0003-004X
DOI
10.2138/am.2006.2154
language
English
LU publication?
yes
additional info
The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Nuclear Physics (Faculty of Technology) (011013007)
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1fa9e5aa-f1eb-453f-96cf-2cfb75c20630 (old id 685742)
alternative location
http://www.minsocam.org.ludwig.lub.lu.se/ProcessIP.lasso?year=2006&filename=Skogby_p1794-1801_06.pdf
date added to LUP
2016-04-01 17:07:10
date last changed
2020-01-30 01:35:09
@article{1fa9e5aa-f1eb-453f-96cf-2cfb75c20630,
  abstract     = {A series of Ti-doped diopside samples synthesized by fluxgrowth methods under reducing conditions were investigated by microanalytical methods and optical absorption spectroscopy, to assess Ti incorporation mechanisms, valence states, and related electronic transitions. Chemical characterization show that Ti occurs both in the tri-and tetravalent states, with Ti4+ preferentially ordered to the tetrahedral position whereas Till is restricted to the M1 position. Charge-balance is maintained by incorporation of Na and minor B, stemming from the flux compound. Polarized optical absorption spectra reveal three major absorption features. Two relatively narrow bands centered at 18 500 and 15 700 cm(-1), mainly polarized in the crystallographic c-direction, display absorbance values that correlate with the calculated Ti3+ (M1) concentration, and are assigned to spin-allowed d-d transitions in Till. A broader band centered around 24 500 cm-1 displays absorbance values that are well correlated with the product of Ti-VI(3+) and Ti-IV(4+). Based on the spectral characteristics of this band, including a strong polarization in the crystallographic b-direction, we assign this band to an Ti-M1(3+)-Ti-T(4+) intervalence charge transfer process.},
  author       = {Skogby, Henrik and Halenius, Ulf and Kristiansson, Per and Ohashi, Haruo},
  issn         = {0003-004X},
  language     = {eng},
  number       = {11-12},
  pages        = {1794--1801},
  publisher    = {Mineralogical Society of America},
  series       = {American Mineralogist},
  title        = {Titanium incorporation and Ti-VI(3+)-Ti-IV(4+) charge transfer in synthetic diopside},
  url          = {http://dx.doi.org/10.2138/am.2006.2154},
  doi          = {10.2138/am.2006.2154},
  volume       = {91},
  year         = {2006},
}