89Y magic-angle spinning NMR of Y2Ti2-xSnxO7 pyrochlores.
J Phys Chem B
; 110(21): 10358-64, 2006 Jun 01.
Article
em En
| MEDLINE
| ID: mdl-16722740
ABSTRACT
The yttrium local environment in the series of pyrochlores Y2Ti2-xSnxO7 was studied using 89Y NMR. Oxides with the pyrochlore structure exhibit a range of interesting physical and chemical properties, resulting in many technological applications, including the encapsulation of lanthanide- and actinide-bearing radioactive waste. The use of the nonradioactive Y3+ cation provides a sensitive probe for any changes in the local structure and ordering with solid solution composition, through 89Y (I = 1/2) NMR. We confirm that a single pyrochlore phase is formed over the entire compositional range, with Y found only on the eight-coordinated A site. A significant (approximately 15 ppm) chemical shift is observed for each Sn substituted into the Y second neighbor coordination environment. The spectral signal intensities of the possible combinations of Sn/Ti neighbors match those predicted statistically assuming a random distribution of Sn4+/Ti4+ on the six-coordinated pyrochlore B site.
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01-internacional
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MEDLINE
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article