利用X射线衍射(XRD)和交流磁化率(Acχ)方法系统地研究了Y1-xEuxBa2Cu3O7-δ(x=0.0～1.0)超导体，研究发现Eu掺杂替代了Y晶位后引起了晶格失配.这种晶格失配与电流密度有密切的联系.对于不同掺杂成分样品，X射线衍射线形分析表明(006)及(007)衍射峰型随掺杂量变化，掺杂浓度在30%和70%附近时，半高宽(FWHM)出现极大值，表明此时样品的晶格失配最大.与此相对应，电流密度Js也在此掺杂浓度范围内达到极大值.我们在晶格失配应力场的钉扎模型下对实验现象进行了讨论，认为Y1-xEuxBa2Cu3O7-δ超导体中由元素替代引起的晶格失配应力场是有效的钉扎中心.
We find Eu substituting Y or Y substituting Eu in Y1-xEuxBa2Cu3O7-δ superconductors causes the lattice mismatch using the methods of X-Ray Diffraction(XRD) and Alternative Current Susceptibility(Acχ). There is a relatively connection between the lattice mismatch and the critical current density Js. The full widths at half maximum(FWHM) of (006) and (007) reflections in the experiment of XRD depend on Eu doping concentration. The maximum of FWHM occurs in the vicinity of x=0.3 and x=0.7, which indicates the lattice mismatch of samples reaches its maximum. Simultaneously, Js also reaches its maximum in the vicinity of x=0.3 and x=0.7. We discuss this experimental phenomenon using the model of stress-field pinning caused by the lattice mismatch. We consider that the lattice mismatch stress-field pinning caused by the lattice mismatch. We consider that the lattice mismatch stree-field, caused by the element substitute in Y1-xEuxBa2Cu3O7-δ superconductors, is an effective pinning center.
参考文献
| [1] | A M Campbell;J.E.Evetts .Flux Vortices and Transport Currents in Type Ⅱ Superconductors[J].Advances in Physics,1972(21):199-428. |
| [2] | S Jin;T H Tiefel;G W Kammlott;R.A.Fastnacht J.E.Graebner .Superconducting properties of YBa2Cu3O7-δ with partial rare earth substitution[J].PHYSICA C,1991,173:75-79. |
| [3] | D N Matthews;J.W.Cochrane;G.J.Russell .Melt-Textured growth and characterisation of a (Nd/Y)Ba2Cu3O7-δ Composite superconductor with very high critical density[J].PHYSICA C,1995,249:255-261. |
| [4] | Louis E Toth;Ira P pratt .STRESS FIELD PINNING BY LOCALIZED COMPOSITION FLUCTUATIONS IN HARD SEMICONDUCTORS[J].Applied Physics Letters,1964,4(04):75-77. |
| [5] | Y Li;N.Chen;Z.X.Zhao .Stree-field pinning induced by lattice mismatch in Y-123 superconductors[J].PHYSICA C,1994,224:391-395. |
| [6] | 李阳;陈宁;赵忠贤;闻海虎 .(RE-Y)-123超导体应力钉扎机制研究[J].低温物理学报,1995(17):277-280. |
| [7] | LI Yang;WANG Yunbo;TANG Chunguang et al.PAT study on stree-field pinning in high-Tc superconductors[J].中国科学A辑(英文版),1997,40(09):978-984. |
| [8] | Yang Li;Chung Tang;Qingzhu Ma et al.Positron Annihilation Study on Stress-field Pinning in (Eu Y)-123 Superconductors[J].Physica C,1997,282-287:2093-2094. |
| [9] | ZHAO Zhongxian;WEN Haihu;LI Yang .Flux pinning induced by lattice-mismatch-stress-field in (RE_(1-x)Y_x)Ba_2Cu_3O_(7-δ) cuprates[J].Science in China.Series A.Mathematics, physics, astronomy,1996(10):1065-1076. |
| [10] | Jianmin Hao;Yeli Wen;Zhengshun Peng et al.The influence of lattice deformation on Jc in epitaxially grown Y1-xHoxBa2Cu3O7-y films[J].Superconductor Science and Technology,1997(10):966-969. |
| [11] | Z S Peng;J.M.Hao;B.Yin et al.The Relationship of Critical Current Density and the Lattice Deformation in Y1-xRExBa2Cu3O7-δ Epitaxial Films[J].Phsica C,1997,282-287:2103-2104. |
| [12] | Wang RL.;Yin B.;Li JW.;Ron XS.;Dong C.;Wu F.;Chen H.;Zhao ZX.;Li HC. .CRITICAL CURRENT DENSITY AND FLUX PINNING IN GD1-XYXBA2CU3O7-Y EPITAXIAL THIN FILMS[J].Physica, C. Superconductivity and its applications,1995(1/2):55-58. |
| [13] | H H Wen;Z.X.Zhao;R.L.Wang;H.C.Li, B.Yin, .Evidence for the lattice-mismatch-stress-field induced flux pinning in (Gd1-xYx)Ba2Cu3O7-δ thin films[J].PHYSICA C,1996,262:81-88. |
| [14] | 杨于兴.X射线衍射分析[M].上海:上海交通大学出版社,1989 |
| [15] | B Büchner;U.Callieβ et al.Correlation of spectroscopic and superconducting properties of REBa2Cu3O7-δ with the rare earth ionic radius[J].Solid State communications,1990,73(05):357-361. |
| [16] | S D Murphy;K.Renouard;R.Crittenden;S.M.Bhagat, .AC Susceptibility of sintered high Tc superconductors-Bean′s model and shielding current[J].Solid State communications,1989,69(04):367-371. |
| [17] | Gencer S Nezir;M Altunbas;A Aydinuraz .AC Susceptibility study of BiPbSrCaCuO(2223) Superconductors[J].Superconductor Science and Technology,1996,9(09):467-473. |
| [18] | S Balat;S Celebi;A.Gencer;H.Cǒmert, E.Yanmaz .The effect of Ag-doping on the magnetic behaviour of Bi-(Ob)-Sr-Ca-Cu-O Ceramic superconductors[J].Journal of Alloys and Compounds,1998,269:1-6. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%