Abstract
High Tc granular superconductors are concrete examples of 3D disordered arrays of coupled junctions. While their static critical properties have been studied to some extent1–2, the study of their critical dynamics properties is still an open subject and it is made difficult by the existence of both intergranular and intragranular junctions3. The difficulty stands in the overlapping between the dynamically-relevant temperature ranges of the two types of junctions. Being mainly interested in the physics of the intergranular connections, we were forced to develop first of all a procedure to select the range of the experimental parameters in such a way to disentangle their own features, as described in ref.3. Our main concern here is devoted to the quasi-equilibrium dynamics of the junction system, that is, the dynamics that can be studied in a situation of uniform magnetic field penetration. By means of a careful examination of the a.c. (both linear and non-linear) susceptibility data, we have recently shown that it is possible to define a temperature range within which the critical dynamics is typical of a fully-pierced intergranular network3. In the recent past, there has been an explosive growth in the number of works dealing with the a.c. susceptibility of the high Tc granular samples, and the interpretations of the experimental data are thereupon spread and suffer of the school of thinking to which each researcher belongs. We can separate them at least in two groups whose opinions are not really in contrast between them but, we believe, rather focused on two different dynamical behaviours: the non-equilibrium4 and the quasi-equilibrium ones5,1. The first group of researchers (whithin which we may distinguish between those that regard the “intergranular matter” as a standard type-II superconductor and those that consider it as a true ensemble of junctions) prefers to cope with those aspects of the dynamics experimentally relevant when the sample is inhomogeneously pierced by the a.c. magnetic field.
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References
C. Giovannella, “Disorder, frustration and critical exponents”, in “Universalities in condensed matter physics”, R. Jullien, R. Peliti, R. Rammal, N. Boccara, ed., Springer Verlag, 1988, P. 93.
C. Giovannella “The superconductor glasses (Sug): a fractal description”, Phys. St. Sol. (b) 154: 273 (1989).
C. Lucchini, C. Giovannella, R. Messi, B. Lecuyer, L. Fruchter, M. Iannuzzi, “A.C. susceptibility and non-lynear dynamics in granular superconductors”, Phys. St. Sol. 2 submitted
S.D. Murphy, K. Renouard, R. Crittenden, S.M. Bhagat, “AC susceptibility of sintered high Tc superconductors - Bean’s model and shielding current”, Sol. St. Comm. 69: 367 (1989)
D.X. Chen, R.B. Goldfarb, “Kim model for magnetization of type-II superconductors” J. Appl. Phys. 66: 2489 (1989)
H. Dersch, G. Blatter,“New critical state model for critical currents in ceramic high Tc superconductors” Phys Rev. B 38: 11391 (1988)
V. Calzona, M.R. Cimberle, C. Ferdeghini, M. Putti, A.S. Ski “A.C. susceptibility and magnetization of high Tc superconductors: critical state model for the intergranular region”, Phys. C 157: 425 (1989)
F. Gomory, S. Takacs, P. Lobotka, K. Frohlich, V. Plechacek, “AC magnetization of high Tc superconductors at low superimposed DC magnetic fields”, Phys. C 160: 1 (1989)
P. Berg, G. Kozlowski, “Numerical calculation of Imaginary Susceptibility in the intergrain region of granular superconductors”, preprint - J.R. Clem, “Phenomenological theory of magnetic structure in the high Tc superconductors”, Physica C, in print - and reference therein
J. Rosenblatt, C. Lebeau, P. Peyral, R. Raboutou,“Disordered three-dimensional arrays of Josephson-junctions” in “Josephson effects-achievements and trends”, ISI, Torino 1985, p. 320.
R.H. Koch, A.P. Malozemoff, “Magnetic properties of high temperature superconductors - implications for 1/f noise in SQUIDs”, in Proc. of 1st International symposium on superconductivity, 1988, and reference therein.
P. Svedlish, P. Granberg, P. Nordblad, L. Lundgren, H.S. Chen, “Relaxation in spin glasses at weak magnetic field”, Phys. Rev. B 35: 268 (1987)
L.P. Levy, A.T. Ogielski, “Non-linear dynamic susceptibility at the spin-glass transition in Ag:Mn” Phys. Rev. Lett. 57: 268 (1986)
M. Ocio, J. Hamman, Ph. Refrgier, E. Vincent, “Experimental investigation of spin glass dynamics in CdInCrS from noise measurements”, Phys. B 150:353 (1988), and reference therein.
L. Lundgren, P. Svedlish, O. Beckman, Phys. Rev. Lett. 51: 911 (1983)
M. Ocio, M. Alba, J. Hamman, “Loi d’échelle des processus de viellissement dans les verres de spins: étude de CsNiFeF”, J. Phys. Lett. 46: L1101 (1985).
R. Hetzel, I. Morgestern, this volume -Rossell C. this volume and reference therein, we note however that the latter paper describes memory-effects in the high magnetic field regime.
L.B.Ioffe, A.I. Larkin, “Properties of superconductors with a smeared transition temperature”, Sov. Phys. Jept. 54: 378 (1981)
D.R. Browman, D. Stroud “Divergent diamagnetism in superconducting and normal metal composites near the percolation threshold”, Phys. Rev. Lett., 52: 299 (1984).
C. Giovannella, C. Lucchini, B. Lecuyer, L. Fruchter, “Non-linear dynamics in a superconductor ‘glass”, IEEE Trans. Magn., 25: 3521 (1989).
K.S. Cole, R.H.Cole, “Dispersion and absorption in dielectrics, alternating current characteristics”, J. of Chem. Phys. 9: 341 (1941).
See S.R. Elliott in this volume and reference therein
K.L. Ngai, “Universality of low frequency fluctuation, dissipation and relaxation properties of condensed matter. I”, Comm Sol. St. Phys. 9: 127 (1979)
Z. Koziol, “Frequency dependent susceptibility of the ceramic YBCO - the spin glass like approach”, Physica C 159: 281 (1989)
M. Continentino, A.P. Malozemoff, “Dynamical susceptibility of spin glasses in the fractal cluster model”, Phys. Rev. B 34: 471 (1986).
I.A. Campbell, “Critical exponents of spin-glass systems”, Phys. Rev. B 37: 9800 (1988).
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Giannelli, A., Giovannella, C. (1990). Quasi-Equilibrium Dynamics and Non-Debye Relaxation in High Tc Granular Superconductors. In: Campbell, I.A., Giovannella, C. (eds) Relaxation in Complex Systems and Related Topics. NATO ASI Series, vol 222. Springer, Boston, MA. https://doi.org/10.1007/978-1-4899-2136-9_16
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