Low-field phenomenology and characteristic lengths of hydrogen- and halogen-doped YBa2Cu3O7-δ compounds

• Published in: Journal of low temperature physics Vol. 116; no. 5-6; pp. 407 - 419
• Main Authors: DEHMEJ, J, FOUAD, Y, GOREN, S. D, BURIN, J. P, PEYRAL, P, ROSENBLATT, J, LEBEAU, C, RABOUTOU, A, MASSIOT, P, PERRIN, C, KORN, C
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 1999; Springer Verlag (Germany)
• Subjects: Condensed Matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cuprates superconductors (high tc and insulating parent compounds); Effects of crystal defects, doping and substitution; Exact sciences and technology; High-Tc compounds; Magnetic properties; Physics; Properties of type I and type II superconductors; Superconductivity; Transition temperature variations; Y-based cuprates; Temperature dependence; Inorganic compounds; Transition element compounds; Doped materials; Experimental study; Penetration depth; Quantity ratio; Halogen addition; Barium oxides; Hydrogen additions; High-Tc superconductors; Quaternary compounds; Copper oxides; Power law; Correlation length; Yttrium oxides; Diamagnetism
• ISSN: 0022-2291; 1573-7357
• DOI: 10.1023/a:1021763626966

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, Tcs, 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.