Electron spin resonance study of the LaIn_3−xSn_xsuperconducting system

Abstract

Abstract. The LaIn 3−x Sn x alloy system is composed of superconducting Pauli paramagnets. For LaIn 3 the superconducting critical temperature T c is approximately 0.7 K and it shows an oscillatory dependence as a function of Sn substitution, presenting its highest value T c ≈ 6.4 K for the LaSn 3 end member.The superconducting state of these materials was characterized as being of the conventional type. We report our results for Gd 3+ electron spin resonance (ESR) measurements in the LaIn 3−x Sn x compounds as a function of x. We show that the effective exchange interaction parameter J f s between the Gd 3+ 4f local moment and the s-like conduction electrons is almost unchanged by Sn substitution and observe microscopically that LaSn 3 is a conventional superconductor.

Possible unconventional superconductivity in substituted BaFe2As2 revealed by magnetic pair-breaking studies

“…For these materials, as discussed in Refs. [31,37], the calculated J 2 (q) AG and the J 2 (q) ESR extracted from ESR experiments are in very good agreement, as expected for a conventional SC. We note that in these compounds, because of the presence of rare earth elements, one needs to properly rewrite the Abrikosov-Gor'kov Equation 1 by replacing S (S + 1) for (g J − 1) 2 J (J + 1), where J = S + L is the total spin.…”

“…A sizeable ESR signal for M = Mn, Cu samples provides not only direct evidence for their role as local magnetic impurities, but it also allows us to extract the averaged exchange coupling J 2 (q) between them and the Fe 3d conduction electrons. The estimated suppression of T c derived from this quantity, which plays the role of the magnetic impurity potential in the Abrikosov-Gor'kov (AG) formalism [29,30], is found to be significantly smaller than the observed one, in sharp contrast to the excellent agreement found previously in borocarbides [31,37,38] -multi-band compounds that display conventional sign-preserving SC states. Furthermore, we find that pressure strongly enhances T c of the M = Cu sample, presumably by promoting stronger Cu-Fe hybridization and consequently suppressing the IPB effect.…”

Probing the localized to itinerant behavior of the4felectron in CeIn3−xSnxBittar1, Adriano2, Giles3 et al. 2012Phys. Rev. B11140View full textAdd to dashboardCite

“…4(a)]. 12 The Gd 3+ relaxation in these alloys is always via a single s-like conduction band and J f s is q independent, decreasing slightly with increasing x (Fig. 7).…”

“…7). 12 For CeIn 3−x Sn x compounds the evolution of the Gd 3+ ESR with Sn substitution is not as straightforward as in LaIn 3−x Sn x . The b and ∆g values change profoundly as a function of x [ Fig.…”

Role of spin-orbit coupling in the physical properties of LaX3 ( X=In , P, Bi) superconductors

“…The Debye temperatures of LaIn 3 and LaPb 3 are derived to be 210 and 125 K, respectively, from specific heat measurements made by Kletowski et al [37]. Recently, an electron spin resonance study [38] of the LaIn 3−x Sn x superconducting system confirms that the T c value of LaIn 3 is around 0.70 K and it exhibits an oscillatory dependence as a function of Sn substitution, reaching its largest value T c ≈ 6.4 K for the LaSn 3 end member.…”