Optical absorption of transition metal ions in silica coating films prepared by the sol-gel technique

1983 ◽  
Vol 2 (8) ◽  
pp. 395-396 ◽  
Author(s):  
S. Sakka ◽  
K. Kamiya ◽  
K. Makita ◽  
Y. Yamamoto
1996 ◽  
Vol 6 (0) ◽  
pp. 241-244 ◽  
Author(s):  
MOHAMED HAOUARI ◽  
HAFEDH BEN OUADA ◽  
HASSEN MAAREF ◽  
HUBERT HOMMEL ◽  
ANDRE PIERRE LEGRAND

Author(s):  
I. Abs-Wurmbach ◽  
K. Langer ◽  
F. Seifert ◽  
E. Tillmanns

AbstractThe crystal chemistry of viridines and kanonaite, (AlThe structure refinements reveal that the transition metal ions substitute for Al almost exclusively in the distorted octahedral Al(l) site of the andalusite structure type within the entire mixed crystal series. This is independently proven by the Mössbauer results for


1968 ◽  
Vol 5 (1) ◽  
pp. 31-38 ◽  
Author(s):  
G. H. Faye

The unpolarized optical absorption spectra of the sheet silicate minerals muscovite, lepidolite, and fuchsite have been examined. The spectra, interpreted on the basis of ligand field theory, indicate that all three minerals contain Fe3+ and possibly Ti3+ in octahedral sites. In addition, muscovite is shown to contain octahedrally coordinated Fe2+, lepidolite octahedral Fe2+ and Mn2+, and fuchsite octahedral Cr3+. No evidence was found for transition metals in tetrahedral sites.Some comments are made on the similarity of the spectra of certain of the transition metal ions in several classes of minerals. This leads to the speculation that the cations Fe3+, Mn2+, and Cr3+ may tend to 'mold' their immediate surroundings.


1997 ◽  
Vol 72-74 ◽  
pp. 417-418 ◽  
Author(s):  
Markus Herren ◽  
Kenji Yamanaka ◽  
Naoya Miyazaki ◽  
Makoto Morita

2011 ◽  
Vol 233-235 ◽  
pp. 2219-2222 ◽  
Author(s):  
Xue Chun Zhong ◽  
Zhan Chang Pan ◽  
Zhi Gang Wei ◽  
Shu Guang Xie ◽  
Zhen Jun Cheng ◽  
...  

In this paper, TiO2crystallines doped with transition metal ions have been prepared by sol-gel method. The UV-visible spectra indicated that the doping with transition metal ions (especially Cu2+, Mn2+and Cr3+ions) could effectively improve the absorption of TiO2crystals in the visible-light range. The XRD results showed that the doping does not affect the anatase phase of TiO2. The band structure and the UV-vis absorption spectrum of Mn2+ions doped-TiO2were also calculated by DFT (density function theory) method, which indicated that the doping with transition metal ion could make the band gap of TiO2smaller and a red shift in optical absorption.


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