Magnetic irreversibility and flux pinning in single crystalline Bi2Sr2Ca1Cu2O8+y

✍ Scribed by C. Quitmann; U. Ebels; P.C. Splittgerber - Hünnekes; G. Güntherodt

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 332 KB
• Volume: 165-166
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/s0921-4526(09)80157-9

✦ Synopsis

We have investigated the magnetic flux-pinning properties of Bi2Sr2CalCu208+Y single crystals using magnetic DC-susceptibility. At low fields (H < 300) the behavior of T*, the irreversibility temperature, is comparable to other high temperature superconductors. Here we find a power law (1-T* ITcJ ~HO. 66 • For higher fields (H > 5 kOe) T* saturates. The value of T* is higher for II .L c than for II lie. to results for YBa2Cu307_x, where the power law is valid up to H ~30 KOe (2), and points to distinct differences between Bi-2212 and the other systems.

& 1;. Reduced irreversibility temperature (1-T* ITcJ vs. effective magnetic field H eff for both principle directions. Solid lines are fits to equation [2] with 1=0.66. H eff = H o -471" * M(emu/cm 3 ) * N [ 1]. Demagnetizing effects are important only for II II c and only at fields below approximately 500 Oe.

In the plot log(1-T* ITcJ vs. log(H eff ) the irreversibility temperature shows a power law behavior for H < 500 Oe,