Abstract
Pyrochlore-type [A{sub 2}{sup VIII}B{sub 2}{sup VI}O{sub 6}O] rare earth stannates (PS) and titanates (PT), doped with increasing amounts of Cr, develop colours ranging from magenta to brown. Combined X-ray and neutron diffraction data revealed that Cr solubility in both pyrochlores is very limited, i.e. 0.07 atoms/formula unit in PS and 0.06 atoms/formula unit in PT. A further increase in the Cr amount determines the formation of the YCrO{sub 3} perovskite. Diffuse reflectance spectroscopy data showed that the optical properties of Cr-doped yttrium titanates and stannates are rather similar, and that the final colour of the powders is due to the overlapping peaks of Cr{sup 4+} in the octahedral site of the pyrochlore and of Cr{sup 3+} in the ternary perovskite. The oxygen occupancy refinement showed that no anion vacancies are formed upon Cr substitution for Sn{sup 4+} or Ti{sup 4+}, implying that such a charge compensation mechanism does not occur, confirming that the Cr in titanate and stannate pyrochlores is mainly in a tetravalent state.
Matteucci, F;
[1]
Cruciani, G;
[2]
Dondi, M;
[1]
Baldi, G;
[3]
Barzanti, A
[3]
- ISTEC-CNR, Institute of Science and Technology for Ceramics, Via Granarolo 64, 48018 Faenza (Italy)
- Department of Earth Sciences, University of Ferrara, Via Saragat 1, 44100 Ferrara (Italy)
- CE.RI.COL., Colorobbia Italia SpA, Via Pietramarina 123, 50053 Vinci (Italy)
Citation Formats
Matteucci, F, Cruciani, G, Dondi, M, Baldi, G, and Barzanti, A.
Crystal structural and optical properties of Cr-doped Y{sub 2}Ti{sub 2}O{sub 7} and Y{sub 2}Sn{sub 2}O{sub 7} pyrochlores.
United Kingdom: N. p.,
2007.
Web.
doi:10.1016/j.actamat.2006.11.008.
Matteucci, F, Cruciani, G, Dondi, M, Baldi, G, & Barzanti, A.
Crystal structural and optical properties of Cr-doped Y{sub 2}Ti{sub 2}O{sub 7} and Y{sub 2}Sn{sub 2}O{sub 7} pyrochlores.
United Kingdom.
https://doi.org/10.1016/j.actamat.2006.11.008
Matteucci, F, Cruciani, G, Dondi, M, Baldi, G, and Barzanti, A.
2007.
"Crystal structural and optical properties of Cr-doped Y{sub 2}Ti{sub 2}O{sub 7} and Y{sub 2}Sn{sub 2}O{sub 7} pyrochlores."
United Kingdom.
https://doi.org/10.1016/j.actamat.2006.11.008.
@misc{etde_21012562,
title = {Crystal structural and optical properties of Cr-doped Y{sub 2}Ti{sub 2}O{sub 7} and Y{sub 2}Sn{sub 2}O{sub 7} pyrochlores}
author = {Matteucci, F, Cruciani, G, Dondi, M, Baldi, G, and Barzanti, A}
abstractNote = {Pyrochlore-type [A{sub 2}{sup VIII}B{sub 2}{sup VI}O{sub 6}O] rare earth stannates (PS) and titanates (PT), doped with increasing amounts of Cr, develop colours ranging from magenta to brown. Combined X-ray and neutron diffraction data revealed that Cr solubility in both pyrochlores is very limited, i.e. 0.07 atoms/formula unit in PS and 0.06 atoms/formula unit in PT. A further increase in the Cr amount determines the formation of the YCrO{sub 3} perovskite. Diffuse reflectance spectroscopy data showed that the optical properties of Cr-doped yttrium titanates and stannates are rather similar, and that the final colour of the powders is due to the overlapping peaks of Cr{sup 4+} in the octahedral site of the pyrochlore and of Cr{sup 3+} in the ternary perovskite. The oxygen occupancy refinement showed that no anion vacancies are formed upon Cr substitution for Sn{sup 4+} or Ti{sup 4+}, implying that such a charge compensation mechanism does not occur, confirming that the Cr in titanate and stannate pyrochlores is mainly in a tetravalent state.}
doi = {10.1016/j.actamat.2006.11.008}
journal = []
issue = {7}
volume = {55}
place = {United Kingdom}
year = {2007}
month = {Apr}
}
title = {Crystal structural and optical properties of Cr-doped Y{sub 2}Ti{sub 2}O{sub 7} and Y{sub 2}Sn{sub 2}O{sub 7} pyrochlores}
author = {Matteucci, F, Cruciani, G, Dondi, M, Baldi, G, and Barzanti, A}
abstractNote = {Pyrochlore-type [A{sub 2}{sup VIII}B{sub 2}{sup VI}O{sub 6}O] rare earth stannates (PS) and titanates (PT), doped with increasing amounts of Cr, develop colours ranging from magenta to brown. Combined X-ray and neutron diffraction data revealed that Cr solubility in both pyrochlores is very limited, i.e. 0.07 atoms/formula unit in PS and 0.06 atoms/formula unit in PT. A further increase in the Cr amount determines the formation of the YCrO{sub 3} perovskite. Diffuse reflectance spectroscopy data showed that the optical properties of Cr-doped yttrium titanates and stannates are rather similar, and that the final colour of the powders is due to the overlapping peaks of Cr{sup 4+} in the octahedral site of the pyrochlore and of Cr{sup 3+} in the ternary perovskite. The oxygen occupancy refinement showed that no anion vacancies are formed upon Cr substitution for Sn{sup 4+} or Ti{sup 4+}, implying that such a charge compensation mechanism does not occur, confirming that the Cr in titanate and stannate pyrochlores is mainly in a tetravalent state.}
doi = {10.1016/j.actamat.2006.11.008}
journal = []
issue = {7}
volume = {55}
place = {United Kingdom}
year = {2007}
month = {Apr}
}