Preparation and structural characterization of rare-earth doped lead lanthanum zirconate titanate ceramics

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• 作者：Thiago Branquinho de Queiroz ; Daniel Mohr ; Hellmut Eckert ; Andrea S.S. de Camargo
• 关键词：Lead lanthanum zirconate titanate ; Rare-earth dopants ; Solid-state NMR
• 刊名：Solid State Sciences
• 出版年：2009
• 出版时间：August 2009
• 年：2009
• 卷：11
• 期：8
• 页码：1363-1369
• 全文大小：796 K

文摘

A new preparation route towards rare-earth (RE) doped polycrystalline lead lanthanum zirconate titanate (PLZT) ceramics (RE = Y³⁺, Nd³⁺, Yb³⁺), based on the use of doped lanthanum oxide or zirconia, is reported. Structural characterization by X-ray powder diffraction reveals that secondary phase formation can be substantially diminished in comparison to conventional preparation methods. The distribution of the rare-earth dopants was investigated as a function of concentration by static ²⁰⁷Pb spin echo NMR spectra, using Fourier Transformation of Carr–Purcell–Meiboom–Gill spin echo trains. For the Nd- and Yb-doped materials, the interaction of the ²⁰⁷Pb nuclei with the unpaired electron spin density results in significant broadening and shifting of the NMR signal, whereas these effects are absent in the diamagnetic Y³⁺ doped materials. Based on different concentration dependences of the NMR lineshape parameters, we conclude that the structural role of the Nd³⁺ dopants differs significantly from that of Yb³⁺. While the Nd³⁺ ions appear to be statistically distributed in the PLZT lattice, incorporation of Yb³⁺ into PLZT appears to be limited by the appearance of doped cubic zirconia as a secondary phase.