Low-Field Phenomenology and Characteristic Lengths of Hydrogen- and Halogen-Doped YBa2Cu3O7−δ Compounds

J. Dehmej , Y. Fouad , Jean-Philippe Burin , P. Peyral , J. Rosenblatt , C. Lebeau , A. Raboutou , P. Massiot , C. Perrin , C. Korn , S.D. Goren (1)

1 Department of Physics [Beer-Sheva]

We measure the diamagnetic response of YBa2Cu3OyAx (A=Cl, F, H) ceramics. We obtain low-field effective penetration depths lambda of a few 10 µm, first flux-penetration field H1 distinguishable from the volume penetration field HC1 and two characteristic temperatures Ts and Tc, Tc<>s, defined by the onset of the real and imaginary parts of the susceptibility, respectively. H1(T) goes to zero as a power law H1(T,x)=H1(0,x)(T-T/Tc)power2.7 near TC. From the values of lambda and H1 we infer the correlation length ksi at T=4.2 K. A large range of values for xgr(4.2) suggests that chemical disorder plays an essential role in the phenomenology of cuprates. We find lambda(4.2)congruent with H1(4.2)-1/3 . This, and the power law ksi(4.2)congruent with H1(4.2)power-2/3 result from the scaling properties of a phase transition governed by disorder.

Domaines: Supraconductivité [cond-mat.supr-con]

J. Dehmej, Y. Fouad, Jean-Philippe Burin, P. Peyral, J. Rosenblatt, et al.. Low-Field Phenomenology and Characteristic Lengths of Hydrogen- and Halogen-Doped YBa2Cu3O7−δ Compounds. Journal of Low Temperature Physics, 1999, 116 (5-6), pp.407. ⟨10.1023/A:1021763626966⟩. ⟨hal-00511810⟩