基于组分Ca2Pr2Cu5O10三元固溶区的范围和晶体结构

宋功保; 韩苍穹; 梁敬魁; 饶光辉

doi:10.11858/gywlxb.2004.01.006

基于组分Ca2Pr2Cu5O10三元固溶区的范围和晶体结构

doi: 10.11858/gywlxb.2004.01.006

1.
西南科技大学材料科学与工程学院，四川绵阳 621002；
2.
中国科学院物理研究所，北京 100080；
3.
中国科学院国际材料物理研究中心，辽宁沈阳 110016

详细信息

通讯作者:
宋功保

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出版历程
- 收稿日期: 2003-05-24
- 修回日期: 2003-09-22
- 刊出日期: 2004-03-05

The Extent and Crystal Structure of the Solid Solution Based on Ca2Pr2Cu5O10

1.
School of Material Science and Engineering, Southwest University of Science and Technology, Mianyang 621002, China;
2.
Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China;
3.
International Center for Materials Physics, Chinese Academy of Sciences, Shenyang 110016, China

More Information

Corresponding author: SONG Gong-Bao

摘要

摘要: 利用X射线衍射分析和Rietveld结构精修方法研究了基于组分Ca2Pr2Cu5O10三元固溶区的范围和晶体结构。根据X射线分析结果和相消失法，为了保持Ca2+xPr2-xCu5O10结构单位晶胞中恒定的氧含量和电价平衡，基于组分Ca2Pr2Cu5O10的三元固溶区的范围可确定为：在Ca2+xPr2-xCu5O10固溶区的富Ca区（Ca/Pr1），其表达式仍可以表示为一般的化学计量式Ca2+xPr2-xCu5O10（x=0.4, 0.2, 0）；在富Pr区（Ca/Pr1），其表达式为Ca1.7Pr2.2Cu5O10、Ca1.4Pr2.4Cu5O10，即：Ca2+xPr2-xCu5O10固溶区范围从Ca2.4Pr1.6Cu5O10至Ca1.4Pr2.4Cu5O10。研究表明：基于组分Ca2Pr2Cu5O10的三元固溶体晶体结构可以看作是正交晶系NaCuO2型亚晶胞的无公度相；Ca2.4Pr1.6Cu5O10亚晶胞的点阵常数为a0=0.282 46(7) nm，b0=0.636 93(1) nm，c0=1.067 94(1) nm；其正交超结构的点阵常数为a=5a0，b=b0，c=5c0。Ca2.4Pr1.6Cu5O10的结构也可以用单斜超晶胞来表述，该单斜超晶胞的空间群为P21/c，Z=4，a=5a0，b=b0，c=c0/sin ，=104.79或136.60，V=5a0b0c0。在基于组分Ca2Pr2Cu5O10的三元固溶体晶体结构中，Ca和Pr之间在一定范围内是可以相互替代的，而且它们在结构中的占位是无序的。
- Ca2Pr2Cu5O10 /
- 三元固溶区 /
- X射线衍射 /
- Rietveld结构精修 /
- 晶体结构
Abstract: The extent and crystal structure of the solid solution based on Ca2Pr2Cu5O10 were studied by X-ray diffraction combined with Rietveld structure refinement. According to the principle of valence neutralization and the disappearing-phase method, in the Ca-rich region (i.e. Ca/Pr1) the composition of solid solution can be expressed as the general stoichiometry Ca2+xPr2-xCu5O10, and in the Pr-rich region (i.e. Ca/Pr1) as Ca1.7Pr2.2Cu5O10, Ca1.4Pr2.4Cu5O10, i. e., the solid solubility of the Ca2Pr2Cu5O10-based solid solution can be determined as from Ca2.4Pr1.6Cu5O10 to Ca1.4Pr2.4Cu5O10. The crystal structure of Ca2Pr2Cu5O10 based solid solution is an incommensurate phase based on the orthorhombic NaCuO2-type subcell. The lattice parameters of Ca2.4Pr1.6Cu5O10 subcell are a0=0.282 46(7) nm, b0=0.636 93(1) nm, c0=1.067 94(1) nm, and its orthorhombic superstructure is with a=5a0, b=b0, c=5c0. The Ca2.4Pr1.6Cu5O10 structure is also determined by using a monoclinic supercell with space group P21/c, Z=4, a=5a0, b=b0, c=c0/sin and =104.79or 136.60, V=5a0b0c0. In the structure of the solid solution based on Ca2Pr2Cu5O10, the mutual substitution between Pr and Ca is possible in some bound. Furthermore, they are distributed disorderly in the structure.
- Ca2Pr2Cu5O10 /
- ternary solid solution /
- X-ray diffraction /
- Rietveld refinement /
- crystal structure

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参考文献(24)

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