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固相线下Pr1-xBa2-yCax+yCu3O7±δ体系的相关系和晶体结构

DOI: 10.11858/gywlxb.2004.04.004, PP. 309-314

Keywords: Pr1-xBa2-yCax+yCu3O7±,&delta,体系,相关系,晶体结构,X射线衍射,Rietveld结构精修

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Abstract:

利用X射线衍射分析和Rietveld结构精修的方法研究了固相线下Pr1-xBa2-yCax+yCu3O7±δ体系的相关系和晶体结构。研究表明:950℃、空气条件下,Pr1-xBa2-yCax+yCu3O7±δ(y=0)体系系列样品总是含有两相:Pr123(PrBa2Cu3O7±δ)和BaCuO2;而且,随Ca含量的增加,杂相BaCuO2的含量也随之增加。Pr1-xBa2-yCax+yCu3O7±δ(x=0)体系y=0.1、0.2、0.3、0.4的样品都只含有Pr123单相;y=0.5的样品含有3相:Pr123、Ca2CuO3和Pr4Ca10Cu24O41。另外,Pr1-xBa2-yCax+yCu3O7±δ(x=0)系列样品(y=0.1、0.2、0.3、0.4)中Pr123相还发生了正交-四方晶系的结构转化。y=0.1和0.2的样品为正交晶系,晶胞参数分别为a=0.39033(4)和0.38936(1)nm,b=0.38953(4)和0.38773(1)nm,c=1.17338(4)和1.16820(2)nm;y=0.3和0.4的样品为四方晶系,晶胞参数分别为a=b=0.38780(0)和0.38767(0)nm,c=1.16600(2)和1.16520(2)nm。在Pr123结构中,Ba离子可以被Pr离子代替,但不能被Ca离子所代替。Ca离子占据部分Pr离子的位置。在Pr1-xBa2-yCax+yCu3O7±δ(x=0)体系中Pr、Ba和Ca离子间的相互替代中,离子半径比化学性质起到了更大的作用。在950℃、空气条件下,Ca离子在Pr1-xBa2-yCax+yCu3O7±δ体系中的最大溶解量是当x=0时,y≤0.4。

References

[1]  Liang J K, Xu X T, Rao G H, et al. Subsolidus Phase Relationships and Superconductivity in the Gd2O3-BaO-CuO system [J]. J Phys D: Appl Phys, 1987, 20: 1324-1326.
[2]  Fu S J, Xie S S, Liang J K, et al. Subsolidus Phase Relations of Nd2O3-BaO-CuO System and Superconductivity of Nd1+xBa2-xCu3Oy(0≤x≤1) [J]. Mod Phys Lett B, 1988, 2: 1073-1078.
[3]  Zhang Y L, Liang J K, Cheng X R, et al. Study of the Phase Relations and Superconductivity in the Ho2O3-BaO-CuO Ternary System [J]. J Less-Commom Met, 1989, 146: 121-125.
[4]  Smith M G, Goodenough J B, Manthiram A, et al. Tin and Antimony Valence States in BaSn0. 85Sb0. 15O3 [J]. J Solid State Chem, 1992, 98: 181-186.
[5]  Liang J K, Chen X L, Wu S L, et al. The Crystal Structure and Property of Ternary Compounds and Phase Relations in the System Yb2O3-BaO-CuO at 950 ℃ [J]. Solid State Commoun, 1990, 74: 509-516.
[6]  Liang J K, Chen X L, Wang X T, et al. The Crystal Structure and Property of Ternary Compound and Phase Relations in the System Pr6O11-BaO-CuO Sintered at 920 ℃[J]. Solid State Commoun, 1990, 76: 903-910.
[7]  Qiao Z Y, Xing X R, Yuan W X, et al. Phase Relations and Compounds in the Sm2O3-BaO-CuO System at 950 ℃ in air [J]. J Alloys and Compounds, 1993, 202: 77-80.
[8]  Tang W H, Gao J. Comparison of Tc-Depression of Pr at Y- and Ba-Sites in YBa2Cu3Oy [J]. Physica C, 1999, 315: 59-65.
[9]  Tang W H, Gao J. High Resistivity of Tetragonal Pr1+xBa2-xCu3Oy Solid Solution [J]. Physica C, 1999, 315: 66-70.
[10]  Yao Y S, Xiong Y F, Jin D, et al. The High-Pressure Synthesis and Superconductivity of Pr0. 5Ca0. 5Ba2Cu3Oz [J]. Physica C, 1997, 282-287: 49-52.
[11]  Young R A, Sakthivel A, Moss T S, et al. DBWS-9411-An Upgrade of the DBWS*. * Programs for Rietveld Refinement with PC and Mainframe Computers [J]. J Appl Cryst, 1995, 28: 366-367.
[12]  Bertrand C, Galez P, Gladyshevskii R E, et al. The Pr(Ba1-xPrx)2Cu3O7+δ Solid Solution. A Crystal Structure and Phase Diagram Study [J]. Physica C, 1999, 321: 151-161.
[13]  Brown I D, Altermatt D. Bond-Valence Parameters Obtained from a Systematic Analysis of the Inorganic Crystal-Structure Database [J]. Acta Crystallogr, 1985, B41: 244-247.
[14]  Che G C, Liang J K, Chen W, et al. Phase Diagram of BaO-Y2O3(La2O3)-CuO Ternary System [J]. Sci Sinica, 1988, 31A: 1079-1092.
[15]  Dong C, Liang J K, Che G C, et al. Superconductivity and Crystal Structure in the La-Ba-Cu-O System [J]. Phys Rev B, 1988, 37: 5182-5185.
[16]  Che G C, Liang J K, Chen W, et al. Phase Diagram of the BaO-CuO-Y2O3 System and the Relationship between Composition and Superconductivity [J]. J Less-Commom Met, 1988, 138: 137-142.
[17]  Hinks D G, Soderholm L, Caponell D W, et al. Phase Diagram and Superconductivity in the Y-Ba-Cu-O System [J]. Appl Phys Lett, 1987, 50: 1688-1690.
[18]  DeLeeuw D M, Mutsaers C A H A, Langereis C, et al. Compounds and Phase Compatibilities in the System Y2O3-BaO-CuO at 950 ℃[J]. Physica C, 1988, 152: 39-49.
[19]  Li K Q, Yao Y S, Cao D H, et al. High Pressure Synthesis of Ca-Doped Pr-123 Superconductors [J]. Physic C, 2000, 341-348: 583-584
[20]  Liang J K, Chen X L, Che G C. Phase Diagram and Phase Structure [M]. Beijing: Science Press, 1993. 1-30. (in Chinese)
[21]  梁敬魁, 陈小龙, 车光灿. 相图与相结构 [M]. 北京: 科学出版社, 1993. 1-30.
[22]  Klug H P, Alexander L E. X-Ray Diffraction Procedures for Polycrystaline and Amorphous Materials (2nd ed) [M]. New York: John Wiley & Sons Inc, 1974. 102-130.
[23]  Xu S S. X-Ray Crystallography [M]. Shanghai: Shanghai Press of Science and Technology, 1962. 47-52. (in Chinese)
[24]  许顺生. X射线晶体学 [M]. 上海: 上海科技出版社, 1962. 47-52.
[25]  Jeniyer A. X-Ray Crystallography [M]. Beijing: Science Press, 1959. 23-30. (in Chinese)
[26]  纪尼叶 A. X射线晶体学 [M]. 北京: 科学出版社, 1959. 23-30.
[27]  Song G B, Han C Q, Chen X L, et al. Subsolidus Phase Relations of PrOx-CaO-CuO System and Structure of Ternary Compounds [J]. J Solid State Chem, 2004, 177(7): 2393-2402.

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