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Johansen, T. H.; Koblischka, Michael Rudolf; Bratsberg, H.; Hetland, Per

doi:10.1103/physrevb.56.11273

Cited by 32 publications

(40 citation statements)

References 29 publications

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“…Similar peak effects have also been observed in many other weak pinning superconductors (see Ref. [11] and references therein). The presence of such a peak effect in Sr 3 Ir 4 Sn 13 may be a signature of additional pinning due to disorder.…”

supporting

confidence: 81%

Superconducting and magnetic properties ofSr3Ir4Sn13

et al. 2014

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Magnetization and muon spin relaxation or rotation (µSR) measurements have been performed to study the superconducting and magnetic properties of Sr3Ir4Sn13. From magnetization measurements the lower and upper critical fields of Sr3Ir4Sn13 are found to be 81(1) Oe and 14.4(2) kOe, respectively. Zero-field µSR data show no sign of any magnetic ordering or weak magnetism in Sr3Ir4Sn13. Transverse-field µSR measurements in the vortex state provided the temperature dependence of the magnetic penetration depth λ. The dependence of λ −2 with temperature is consistent with the existence of single s-wave energy gap in the superconducting state of Sr3Ir4Sn13 with a gap value of 0.82(2) meV at absolute zero temperature. The magnetic penetration depth at zero temperature λ(0) is 291(3) nm. The ratio ∆(0)/kBTc = 2.1(1) indicates that Sr3Ir4Sn13 should be considered as a strong-coupling superconductor.PACS numbers: 74.25. Ha, 74.70.Dd, 76.75.+i Recently, ternary intermetallic stannide compounds, R 3 Ir 4 Sn 13 , where R = Ca, Sr, etc., have attracted renewed interest because of the coexistence of superconducting and charge density wave states and the possible presence of pressure induced quantum structural phase transitions.

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confidence: 81%

Superconducting and magnetic properties ofSr3Ir4Sn13

et al. 2014

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“…4 were computed for the superconductor with a rectangular cross section as in the first example for three different models: the Bean model, the Kim model, and a model with a secondary peak in the J c (•) dependence. In the latter case the critical current density was taken similar to that in Johansen et al 19 ; that is, J c (s) = (1+ In conclusion, we note that although quasi-variational inequalities, arising in critical-state problems with critical current density depending on the magnetic field, are much more difficult mathematical problems than the variational inequalities arising in Bean's model, their numerical solution based on the dual formulation presented in this work is practically as efficient as the solution of the Bean model problems in Barrett and Prigozhin 6 . …”

Section: Convergence Of (Qmentioning

confidence: 99%

“…There are also materials demonstrating a secondary peak in their magnetisation hysteresis loops. The latter phenomenon, often called "the fishtail effect", can be described by the eddy current model with a non-monotonic J c (|b|) dependance; see, e.g., Johansen et al 19 . We mention here also the primal variational formulation for a generalized double critical-state model, see Badía and Lopez 2 and Kashima 20 , in which Φ is the characteristic function of the set of admissible currents satisfying j(x, t) ∈ Δ(b(x, t)) and Δ(b) ⊂ R 3 being a given family of closed convex sets.…”

Section: Primal Problemmentioning

confidence: 99%

A Quasi-Variational Inequality Problem in Superconductivity

Barrett

Prigozhin

2010

Math. Models Methods Appl. Sci.

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Received RevisedWe derive a class of analytical solutions and a dual formulation of a scalar two space dimensional quasi-variational inequality problem in applied superconductivity. We approximate this formulation by a fully practical finite element method based on the lowest order Raviart-Thomas element, which yields approximations to both the primal and dual variables (the magnetic and electric fields). We prove subsequence convergence of this approximation, and hence prove existence of a solution to both the dual and primal formulations, for strictly star-shaped domains. The effectiveness of the approximation is illustrated by numerical examples with and without this domain restriction.

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“…The fish-tail effect has also been observed in various magnetization measurements of superconductors [22][23][24][25]. Some phenomenological models based on critical-state model were presented in literature to describe this effect in magnetization data [26][27][28][29][30][31].…”

Section: Introductionmentioning

confidence: 93%