Vortex avalanche phenomena in MgB2 superconducting film studied by current noise measurements

Eggenhöffner, R.; Celasco, E.; Ferrando, V.; Celasco, M.
January 2005
Applied Physics Letters;1/10/2005, Vol. 86 Issue 2, p022504
Academic Journal
Vortex avalanche phenomenon enhanced by thermomagnetic instabilities suppresses critical current in MgB2 films. This effect is investigated at 4.2 K by spectral noise power measurements up to 1 kHz with a dc superconducting quantum interference device apparatus. 1/fγ behavior is shown at low frequencies in magnetic fields and feeding currents below jc. γ increases from 1 to 2 at increasing magnetic field, typical of fluxon avalanche processes. A peak in the power spectrum frequency behavior, observed only in magnetic field, is attributed to vortex–antivortex annihilations. Thermal instabilities disappear when an efficient thermal link to the He bath is attained and no vortex avalanche extra-noise is observed.


Related Articles

  • Josephson effect in MgB2/Pd/Fe/Nb Josephson junctions. Malisa, A. // Applied Physics Letters;11/21/2005, Vol. 87 Issue 21, p213504 

    MgB2/Pd/Fe/Nb Josephson junctions were fabricated and characterized. The junctions exhibited the Josephson effect. A supercurrent was observed across the magnetically active layer formed at the Pd and Fe interface and also across the magnetic metal Fe itself. Shapiro steps and fractional Shapiro...

  • Noise in MgO barrier magnetic tunnel junctions with CoFeB electrodes: Influence of annealing temperature. Scola, J.; Polovy, H.; Fermon, C.; Pannetier-Lecœur, M.; Feng, G.; Fahy, K.; Coey, J. M. D. // Applied Physics Letters;6/18/2007, Vol. 90 Issue 25, p252501 

    Low frequency noise has been measured in magnetic tunnel junctions with MgO barriers and magnetoresistance values up to 235%. The authors investigated the noise for different degrees of crystallization and CoFeB/MgO interface quality depending on the annealing temperature. The authors report an...

  • Lower bound for the superheating field in the weak-κ limit: The general case. Del Castillo, Pierre // Journal of Mathematical Physics;Jun2003, Vol. 44 Issue 6, p2416 

    We have constructed asymptotic matched solutions for the one dimensionnal Ginzburg–Landau system when κ is small [Math. Model. Num. Anal. 36, 971–993 (2002)]. We have deduced an expansion in powers of κ[sup 1/2] at all orders for the superheating field. In this paper, using...

  • Magnetic field dependence of quasiparticle losses in a superconductor. Ullom, J. N.; Fisher, P. A.; Nahum, M. // Applied Physics Letters;10/26/1998, Vol. 73 Issue 17 

    We have studied the propagation of quasiparticles in a superconducting film which is penetrated by a magnetic field. We inject quasiparticles into an Al film at 75 mK using a normal–insulator–superconductor tunnel junction and measure the flux of quasiparticles which diffuse into...

  • Magnetic Shielding Properties of MgBFe Superimposed Systems. Gozzelino, L.; Gerbaldo, R.; Ghigo, G.; Laviano, F.; Agostino, A.; Bonometti, E.; Chiampi, M.; Manzin, A.; Zilberti, L. // Journal of Superconductivity & Novel Magnetism;May2013, Vol. 26 Issue 5, p1513 

    We studied the magnetic shielding properties of a MgB/Fe hybrid structure consisting of two coaxial cups subjected to a magnetic field applied parallel to their axis. This study was performed to analyze the magnetic shield properties of a system contemporary exploiting the opposite magnetic...

  • MgB Thin Films on Metal Substrates for Superconducting RF Cavity Applications. Zhuang, Chenggang; Tan, Teng; Krick, Alex; Lei, Qingyu; Chen, Ke; Xi, X. // Journal of Superconductivity & Novel Magnetism;May2013, Vol. 26 Issue 5, p1563 

    Magnesium diboride is a promising material for superconducting RF (SRF) cavity applications. Compared to the currently used superconductor for SRF cavities Nb, MgB has the potential to achieve lower RF loss and higher acceleration field due to its higher critical temperature and thermodynamic...

  • The Upper Critical Field H in Advanced Superconductors with Anisotropic Energy Spectrum. Palistrant, M. // Journal of Superconductivity & Novel Magnetism;Dec2010, Vol. 23 Issue 8, p1427 

    brief review of works on the microscopic theory of determining the upper critical field in two-band isotropic and anisotropic superconductors is given. The research is based on a set of the Ginzburg-Landau equations for the order parameters in a magnetic field that are studied in terms of the...

  • Irreversibility Effects and Low Field Magnetovoltage Measurements in Superconducting MgB Near the Critical Temperature T. Olutaş, M.; Kiliç, A.; Kiliç, K.; Altinkok, A. // Journal of Superconductivity & Novel Magnetism;Dec2013, Vol. 26 Issue 12, p3369 

    We have investigated the hysteresis effects in magnetovoltage measurements ( V- H curves) in a polycrystalline superconducting MgB near critical temperature T. The measurements were carried out as functions of temperature ( T) and transport current ( I), and sweep rates of the external magnetic...

  • The Effect of Anisotropy of H on Transport Current in Silicone Oil-Doped MgB Superconductor. Ghorbani, S.; Fahimi, M. // Journal of Superconductivity & Novel Magnetism;Jun2015, Vol. 28 Issue 6, p1737 

    The temperature and magnetic field dependences of the critical current density in silicone oil-doped MgB polycrystalline samples have been investigated by magnetic measurements. The upper critical magnetic field anisotropy, $\gamma =H_{\mathrm {c}2}^{\bot \mathrm {c}}/H_{\mathrm {c}2}^{\vert...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics