Periodic magnetization instabilities in a superconducting Nb film with a square lattice of Ni dots

Terentiev, A.N.; Watkins, Byron; Long, L. E. De; Cooley, L. D.; Morgan, D. O.; Ketterson, J. B.

doi:10.1016/s0921-4534(99)00636-x

Cited by 10 publications

(12 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…24). Additional evidence of an increase of the critical current at low temperatures (far from the superconducting/normal phase boundary) produced by magnetic dots was reported by Terentiev et al [248,249,250].…”

Section: Mechanisms Of Pinning In S/f Hybridsmentioning

confidence: 59%

Nucleation of superconductivity and vortex matter in superconductor–ferromagnet hybrids

Aladyshkin

Silhanek

Gillijns

et al. 2009

Supercond. Sci. Technol.

218

143

View full text Add to dashboard Cite

Abstract. The theoretical and experimental results concerning the thermodynamical and low-frequency transport properties of hybrid structures, consisting of spatially-separated conventional low-temperature superconductor (S) and ferromagnet (F), is reviewed. Since the superconducting and ferromagnetic parts are assumed to be electrically insulated, no proximity effect is present and thus the interaction between both subsystems is through their respective magnetic stray fields. Depending on the temperature range and the value of the external field Hext, different behavior of such S/F hybrids is anticipated. Rather close to the superconducting phase transition line, when the superconducting state is only weakly developed, the magnetization of the ferromagnet is solely determined by the magnetic history of the system and it is not influenced by the field generated by the supercurrents. In contrast to that, the nonuniform magnetic field pattern, induced by the ferromagnet, strongly affect the nucleation of superconductivity leading to an exotic dependence of the critical temperature Tc on Hext. Deeper in the superconducting state the effect of the screening currents cannot be neglected anymore. In this region of the phase diagram various aspects of the interaction between vortices and magnetic inhomogeneities are discussed. In the last section we briefly summarize the physics of S/F hybrids when the magnetization of the ferromagnet is no longer fixed but can change under the influence of the superconducting currents. As a consequence, the superconductor and ferromagnet become truly coupled and the equilibrium configuration of this "soft" S/F hybrids requires rearrangements of both, superconducting and ferromagnetic characteristics, as compared with "hard" S/F structures. Some figures in this paper are in color only in the electronic version.

show abstract

Section: Mechanisms Of Pinning In S/f Hybridsmentioning

confidence: 59%

Nucleation of superconductivity and vortex matter in superconductor–ferromagnet hybrids

Aladyshkin

Silhanek

Gillijns

et al. 2009

Supercond. Sci. Technol.

218

143

View full text Add to dashboard Cite

show abstract

“…Heterogeneous ferromagnetic-superconducting ͑FM-SC͒ systems have attracted much attention recently [1][2][3][4][5][6][7][8][9][10][11][12][13][14] If the proximity effect is suppressed by the oxide layer between the FM and SC components, they interact via magnetic field. Any inhomogeneous magnetization produces magnetic field penetrating into the superconductor and inducing supercurrents.…”

Section: Introductionmentioning

confidence: 99%

Superconducting transition temperature in heterogeneous ferromagnet-superconductor systems

Pokrovsky¹,

Wei²

2004

Phys. Rev. B

View full text Add to dashboard Cite

We study the superconducting phase transition in two systems: ferromagnet-superconductor bilayer ͑FSB͒ and a thin superconducting film with a periodic array of magnetic dots ͑SFMD͒ upon it. We show that this transition is of the first order in FSB and of the second order in SFMD. The shift of the transition temperature ⌬T c due to the presence of a ferromagnetic layer may be positive or negative in the FSB and is always negative in the SFMD. The dependence of ⌬T c on geometrical factors and external magnetic field is found. Theory is extended to multilayers.

show abstract

“…We focus our analysis on the data obtained within the range of temperatures 7.5K < T < 7.52K < T c , where T c ≃ 7.55K is the superconducting critical temperature of the sample, and the range of current densities 10A/cm 2 < J < 27A/cm 2 . For lower temperatures or currents the commensurability effects are weak, presumably due to the dominance of the intrinsic pinning mechanisms over the periodic potential [39,40,41]. For temperatures or currents above the selected intervals, we observed a finite dissipation at zero external magnetic field which indicates the presence of vortices induced by the external current or other dissipation mechanisms.…”

Section: Magnetoresistance Measurementsmentioning

confidence: 75%

Vortex kinks in superconducting films with periodically modulated thickness

Facio¹,

Abate²,

Guimpel³

et al. 2013

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

We report magnetoresistance measurements in Nb films having a periodic thickness modulation. The cylinder shaped thicker regions of the sample, which form a square lattice, act as repulsive centers for the superconducting vortices. For low driving currents along one of the axes of the square lattice, the resistivity ρ increases monotonously with increasing magnetic field B and the ρ–B characteristics are approximately piecewise linear. The linear ρ versus B segments change their slope at matching fields where the number of vortices is an integer or a half integer times the number of protruding cylinders in the sample. Numerical simulations allow us to associate the different segments of linear magnetoresistance to different vortex-flow regimes, some of which are dominated by the propagation of discommensurations (kinks).

show abstract

Periodic magnetization instabilities in a superconducting Nb film with a square lattice of Ni dots

Cited by 10 publications

References 22 publications

Nucleation of superconductivity and vortex matter in superconductor–ferromagnet hybrids

Nucleation of superconductivity and vortex matter in superconductor–ferromagnet hybrids

Superconducting transition temperature in heterogeneous ferromagnet-superconductor systems

Vortex kinks in superconducting films with periodically modulated thickness

Contact Info

Product

Resources

About