Flux pinning with a magnetic nanorod array

Abstract

We report measurements of the phase diagram and critical current of a PbBi superconducting film with an embedded square array of Ni nanorods. Strong hysteresis of the superconducting properties and an increase in the critical current which varies from several times to several orders of magnitude depending on the magnetic field and temperature is found.

Temperature- and field-dependent critical currents in [(Bi,Pb)2Sr2Ca2Cu3Ox]0.07(La0.7Sr0.3MnO3)0.03 thick films grown on LaAlO3 substrates

“…Such inhomogeneous distribution of the magnetic field into the superconductor may pin the vortices and lead to dramatic changes in its electrical and magnetic properties. 3,[10][11][12][13] Indeed, inhomogeneous field distribution in the superconductor produces different values of the critical magnetic field H c2 and superconducting critical currents in different directions. Furthermore, the presence of an FM in the neighborhood of the SC strongly affects its superconducting properties due to the destructive interaction between spin-polarized carriers and Cooper pairs.…”

“…Different SC/FM arrays such as ordered two-dimensional arrays of ferromagnetic dots and nanodots, and SC/FM heterostructures have been proposed for studying the magnetoelectrical behavior of hybrid systems. 3,[10][11][12][13][14] The sizeable suppression of T c and T C (Curie temperature) observed for SC/FM superlattices with relatively thick layers (d YBCO,LCMO > 10 nm) suggested that the proximity coupling involves an unexpectedly large length scale, far in excess of the SC coherence length of n c (0) 2 nm. 15 Optical measurements on SC/FM superlattices evidenced that the freecarrier response in these superlattices was strongly suppressed as compared to the pure films of which they consisted.…”

Tunability of the critical-current density in superconductor-ferromagnet hybrids

“…1͒ but in the space between them, where the dots field has the opposite polarity. 21,22 Although the geometry of our simulated system is not exactly the same as in the experimental case ͑we consider infinitely long PMs instead of an array of magnetic dots and only consider a fragment of SC on top of two PMs͒ when taking into account a equivalent space between dots with reversed field, we show in Fig. 2 a calculated M͑H At this point we can ask whether the described behavior is the only possible effect that a PM can create on the hysteresis loop of a SC.…”

Phase-Field Simulation of Superconductor-Ferromagnet Bilayer-Based Cryogenic Strain Sensor

“…Whereas only magnetostatic coupling (through the stray field of FM layer and magnetization of vortices in SC layer) is responsible for long-range proximity effect by prohibiting electrical coupling by the introduction of a barrier between SC and FM layers, generally a buffer layer of a suitable thickness is introduced. Recently, the effect of magnetic domain structures on the SC layer with emphasis on flux pinning has been reported using arrays of magnetic dots [6], magnetic templates [7], punch holes [8], magnetic nanorod array [9,10], magnetic stripes [11], domain width [12], and magnetic micro loops [13]. Such bilayer devices have also been proposed to be a candidate of memristor devices [14] and studied for superconductivity manipulation using FM domain structures with [15] and without [16,17] buffer layer.…”