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制备了银包套的Bi1.8Pb0.4Sr2Ca2.2Cu3Oy带材。微结构观察证明样品是高度织构化的Bi2223单相。输运测量发现Jc(T,B,θ,φ)和R(T,B,θ,φ)均与θ有关,与φ无关(T=77K,B<1T),式中的θ和φ分别表示磁场与ab面和电流的夹角。求得了磁通运动的激活能。提出了热激活磁通弯结的形成与运动模型,并用London理论计算了弯结Ag-sheathed Bi1.8Pb0.4Sr2Ca2.2Cu3Oy superconducting tapes were prepared. Microstruc-ture examination shows that it were made of highly textured Bi2223 single phase. Measurements of transport properties in liquid nitrogen and field lower than 1T reveal that Jc(T,B,θ, φ) and R(T,B,θ,φ) of this material are θ dependent and φ independent, where θ is the angle between magnetic field and ab plane and φ is the angle between magnetic field and transport current. Activation energy of flux lines was gained. The Arrhenius relation of R(T,B) was observed and activation energy of flux motion was determined. The transport characteristics and the activation energy are explained as the thermally activated flux line diffusive motion over intrinsic flux pinning barrier by means of nucleation of two-dimensional pancake vortex pairs.







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