Scandium Coordination in Solid Oxides and Stabilized Zirconia: 45Sc NMR

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• 作者：Namjun Kim ; Cheng-Han Hsieh ; Jonathan F. Stebbins
• 刊名：Chemistry of Materials
• 出版年：2006
• 出版时间：August 8, 2006
• 年：2006
• 卷：18
• 期：16
• 页码：3855 - 3859
• 全文大小：87K
• 年卷期：v.18,no.16(August 8, 2006)
• ISSN：1520-5002

文摘

⁴⁵Sc NMR isotropic chemical shifts and quadrupole coupling constants of several scandium-containingsolid oxides have been measured. Both parameters prove to be sensitive to local structure. In particular,in these materials the ⁴⁵Sc isotropic chemical shift appears to be dominated by the first neighborcoordination environment, i.e., the coordination number. The difference in the isotropic shifts betweensix-coordinated and eight-coordinated scandium is more than 150 ppm, suggesting that this parametermay be especially useful in studying the scandium coordination in oxide materials, disordered solids inparticular. Quadrupole coupling constants are sensitive to the nature of the second coordination cation,although many other structural details may play a role. The chemical shift correlation was applied toscandia-stabilized zirconia, (ZrO₂)_0.92(Sc₂O₃)_0.08, and the mean coordination number obtained appears tobe close to seven, which suggests the possibility of two scandium cations pairing with one vacancy.