Superconductivity, magnetic ordering, and its interplay in HoNi211B2C

Abstract

We investigated the low-temperature properties of polycrystalline HoNi2 11 B2C by means of ac-susceptibility and neutron powder diffraction in the temperature range of 1.5 to 10 K and zero magnetic field. A sample with pronounced re-entrant behaviour was chosen since it exhibits a superconducting state which is strongly affected by the intrinsic magnetism, the formation of long range magnetic order, via pair-breaking. The evolution and volume fractions of the three different magnetic structures were observed and correlated to the superconducting behaviour.

Microscopic changes inHoNi2B2Cdue to thermal treatment and its effect on superconductivity

“…The transition temperature of the second piece annealed at 1100°C is about 1 K lower (T c,90% ϭ8.30 K) with a similarily sharp transition width of ⌬T c ϭ0.30 K. Correlated with the lower transition temperature, a tiny reentrant maximum can be seen at 5.29 K near the magnetic transitions. 11,18 The superconducting properties of these samples are comparable to those of single crystals. 15 The very sharp transitions indicate a high sample quality.…”

“…8,[10][11][12] Both superconducting and magnetic properties of HoNi 2 B 2 C strongly depend on its composition within the small but nonnegligible homogeneity range for this quaternary compound. 13 While for flux-grown single crystals only an ordinary superconducting transition at always the same transition temperature has been observed in zero magnetic field, 14,15 there exists a variety of different low-temperature behaviors for polycrystalline samples: a pure superconducting state ͑coexistent with antiferromagnetic order͒, a nonsu-perconducting magnetically ordered state as well as reentrant behavior, governed by the chemical composition within the homogeneity range.…”

Possibility of a π Josephson junction and switch in superconductors with spiral magnetic order

“…min E J is reached for ϕ = π. Eq. (5,6) imply also that for χ = −1 the case R χ < −1 is realized in some region of m and p (see Figs. (2-3)) and the π-contact is realized for those θ with cos θ < −1/ | R χ |.…”

“…From Eqs. (5,6) comes out that for | R χ |> 1 the π-junction is realized, i.e. min E J is reached for ϕ = π. Eq.…”

Decoupling of superconducting layers in the magnetic superconductorRuSr2GdCu2OHouzet1, Buzdin2, Kulić3 2001Phys. Rev. B220200View full textAdd to dashboardCite

“…In most of the new quaternary rare-earth compounds (RE)Ni 2 B 2 C the antiferromagnetic order and superconductivity coexist up to T = 0 K [4], while in HoNi 2 B 2 C an additional oscillatory magnetic structure is realized in a limited temperature interval. This oscillatory magnetic structure competes strongly with superconductivity giving rise to reentrant behavior in this compound [5]. Recently the Pobell´s group in Bayreuth [6] made a remarkable discovery of the coexistence of superconductivity and nuclear magnetic order in AuIn 2 with T c = 0, 207 K and T m = 35µ K .…”