CRYSTAL-GROWTH, CRYSTAL-STRUCTURE AND CHEMICAL-COMPOSITION OF A PYROCHLORE TYPE COMPOUND IN LEAD-MAGNESIUM-NIOBIUM-OXYGEN SYSTEM

被引:39
作者
WAKIYA, N
SAIKI, A
ISHIZAWA, N
SHINOZAKI, K
MIZUTANI, N
机构
[1] TOKYO INST TECHNOL,FAC ENGN,DEPT INORGAN MAT,2-12-1 O OKAYAMA,MEGURO KU,TOKYO 152,JAPAN
[2] TOKYO INST TECHNOL,ENGN MAT RES LAB,MIDORI KU,YOKOHAMA,KANAGAWA 227,JAPAN
关键词
PYROCHLORE; LEAD; MAGNESIUM; NIOBIUM;
D O I
10.1016/0025-5408(93)90082-O
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The single crystal of pyrochlore type compound in Pb-Mg-Nb-0 system (Pb1.86Mg0.24Nb1.76O6.5) was grown by using a PbO flux. The space group is Fd3m with a=1.06029(2)nm, V=1.19200(1)nm3, Z=8, Dx=7.34gcm-3 and mu(MoK(alpha))=547.28cm-1. Both oxygen vacancies and cations arc not ordered. Refined final R and Rw are 3.08% and 2.83% respectively for 213 independent reflection data collected on a four-circle X-ray diffractometer. The crystal is characterized by the pyrochlore structure having deficient Pb at the A(8d) site and deficient 0 al the 0(2)(8B) site. Mg and Nb statistically occupy the B(8c) site. The oxygen content 6.5 seems common in this type of compounds.
引用
收藏
页码:137 / 143
页数:7
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