Tosi, L., E. Osquiguil, E. E. Kaul, and C. A. Balseiro. "Barkhausen-type noise in the resistance of antiferromagnetic Cr thin films." Europhysics Letters 100 (2012): 67005.
Abstract: We present an experimental study of the changes generated on the electrical resistance R(T ) of epitaxial Cr thin films by the transformation of quantized spin density wave domains as the temperature is changed. A characteristic resistance noise appears only within the same temperature region where a cooling-warming cycle in R(T ) displays hysteretic behavior. We propose an analysis based on an analogy with the Barkhausen noise seen in ferromagnets. There fluctuations in the magnetization M (H) occur when the magnetic field H is swept. By mapping
M → Ψ0 and H → T , where Ψ0 corresponds to the order parameter of the spin density wave, we generalize the Preisach model in terms of a random distribution of resistive hysterons to explain our results. These hysterons are related to distributions of quantized spin density wave domains with different sizes, local energies and number of nodes.
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Núñez Regueiro, M., O. Bethoux, J. - M. Mignot, P. Monceau, P. Bernier, C. Fabre, and A. Rassat. "Electrical Resistivity of Fullerenes at High Pressures." Europhysics Letters 21, no. 1 (1993): 49–53.
Abstract: We have measured the electrical resistivity as a function of temperature up to pressures of 25 GPa of pure fullerenes C60, C70 and the compound C60I4. For the three materials the best fit in our temperature range corresponds to a three-dimensional variable-range hopping conductivity, signature of an important disorder. A dramatic decrease of the resistivity, by two orders of magnitude per GPa, is observed at low pressures. However, no metallic state is attained as all the samples present a phase transformation in the high-pressure range, probably originated by the crossover from sp2 to sp3 hybridization of the carbon orbitals at high pressures.
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Núñez Regueiro, M., J. - M. Mignot, and D. Castello. "Superconductivity at High Pressure in NbSe3." Europhysics Letters 18, no. 1 (1992): 53–57.
Abstract: We have measured the electrical resistivity of NbSe3 between 2 K and room temperature up to a pressure of 7.2 GPa. At P1 = 3.5 GPa we observe the extinction of the high-temperature charge density wave (T1-CDW) and the enhancement of the superconducting critical temperature Tc to [?] 5 K. The logarithmic pressure slopes of T1 (P < P1) and Tc (P > P1) are found to be practically equal. A similar behaviour had been reported previously at lower pressures for T2 (P < P2) and Tc (P2 < P < P1) in the distorted state. We discuss these results in terms of an anisotropic superconducting state in NbSe3, with different gaps associated with different types of chains.
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M. Skoulatos, J. P. Goff, C. Geibel, E. E. Kaul, R. Nath, N. Shannon, B. Schmidt, A. P. Murani, P. P. Deen, M. Enderle y A. R. Wildes. "Spin correlations and exchange in square-lattice frustrated ferromagnets." Europhysics Letters 88 (2009): 57005.
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D'Anna, G., W. Benoit, J. Luzuriaga, and H. Berger. "Dynamic and static mechanical measurements of flux-lattice softening and associated hysteretic depinning dissipation peak in YBa2Cu3Ox ceramic." Europhysics Letters 13, no. 5 (1990): 465–471.
Abstract: We have studied flux-lattice dissipation in YBa2Cu3Ox ceramic using a forced inverted torsional pendulum. Reversible restoring force variations during temperature sweep suggest that flux lines experience a “hard-soft” transition between 50 K and Tc. Measurements of internal friction and modulus change as a function of the applied stress show a typical depinning behaviour. This dissipation peak during the temperature sweep is understood as a hysteretic depinning in which the critical force depends upon the penetration depth.
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Correa, V. F., N. Haberkorn, G. Nieva, D. J. García, and B. Alascio. "Unusual large magnetostriction in the ferrimagnet Gd2/3Ca1/3MnO3." EUROPHYSICS LETTERS 98 (2012): 37003.
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