Neutron diffraction and IR spectroscopy on mechanically alloyed La-substituted PbWO4
Neutron diffraction and IR spectroscopy on mechanically alloyed La-substituted PbWO4
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DOI：
10.1016/j.ssi.2004.03.008
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发表时间：
2004-05-31
影响因子：
3.2
通讯作者：
Esaka, T
中科院分区：
文献类型：
--
作者：
Takai, S;Nakanishi, T;Esaka, T
采用粉末中子衍射和傅立叶变换红外光谱（FT-IR）研究了机械合金化（MA）制备的镧掺杂钨酸铅（PbWO 4）的缺陷结构，并与氧离子导电烧结样品的缺陷结构进行了比较。中子衍射结果表明，MA法制备的Pb_（1-x）La_xWO_（4+）（x/2）在晶格中存在铅位缺陷。此外，还发现即使对于机械合金化的Pb 1-xLa 2 x/3 WO 4，铅位的占据因子仍然小于标称值。机械合金化Pb_（1-x）La_xWO_（4 + x/2）铅位空位的形成也由WO_4四面体的W-O伸缩振动引起的800 cm ~（-1）附近吸收带的分裂得到证实。本文最后讨论了球磨过程中Pb_（1-x）LaWO_（4 + x）/2烧结体中铅位空位的形成过程。(C)2004 Elsevier B. V.保留所有权利。
Defect structures of the lanthanum-substituted PbWO4 prepared by mechanical alloying (MA) were investigated by means of powder neutron diffraction and FT-IR, to compare with that of the oxide ion conductive sintered samples. Neutron diffraction revealed that Ph1-xLaxWO4 + (x/2) prepared by MA possessed the lead site deficiency in the lattice. In addition, it was also found that occupation factors of the lead site were still smaller than the nominal value even for the mechanically alloyed Pb1-xLa2x/3WO4. The vacancy formation at the lead site of the mechanically alloyed Pb1-xLaxWO4 + x/2 was also corroborated from the splitting of the absorption band around 800 cm(-1) ascribed to the W-O stretching vibration Of WO4 tetrahedron. At the end of this paper, the formation process of the lead site vacancy was discussed in the sintered Pb1 - xLaWO4 + x/2 during milling. (C) 2004 Elsevier B.V. All rights reserved.