Point-contact spectroscopy of superconducting energy gap in $\mathrm{DyN}{\mathrm{i}}_2{\mathrm{B}}_2\mathrm{C}$

Abstract

The superconducting energy gap in $\mathrm{DyN}{\mathrm{i}}_2{\mathrm{B}}_2\mathrm{C}$ has been investigated using a point-contact technique based on the Andreev reflection from a normal (N)-superconductor (S) boundary, where N is Ag. The observed differential resistance $dV/dI$ is well described by the Blonder-Tinkham-Klapwijk (BTK) theory based on the BSC density of states with zero broadening parameter. Typically, the intensity of the gap structure amounts to several percentage of the normal state resistance, which is an order of magnitude less than predicted by the theory. For $\mathrm{DyN}{\mathrm{i}}_2{\mathrm{B}}_2\mathrm{C}$ with $T_c<T_N$ (the Neel temperature), we found gap values satisfying the ratio of $2{\Delta }_0/k_B{T}_c=3.63\pm 0.05$ similar to other superconducting nickel-borocarbides, both nonmagnetic and magnetic with $T_c\ge T_N$. The superconducting gap nonlinearity is superimposed on the antiferromagnetic structure in $dV/dI(V)$ which is suppressed at the magnetic field of the order of 3T applied nominally in the $ab$-plane and temperature $\ge 11K$. The observed superconducting properties depend on the exact composition and structure at the surface of the crystal.

8 pages, 13 figures

References in corpus (1)

• Electron-quasiparticle interaction in $\mathrm{DyN}{\mathrm{i}}_2{\mathrm{B}}_2\mathrm{C}$ measured by point-contact spectroscopy

Cited by in corpus (3)

• The role of critical current on point contact Andreev Reflection spectrum between a normal metal and a superconductor
• Point-contact spectroscopy of the antiferromagnetic superconductor HoNi2B2C in the normal and superconducting state
• Electron-quasiparticle interaction in $\mathrm{DyN}{\mathrm{i}}_2{\mathrm{B}}_2\mathrm{C}$ measured by point-contact spectroscopy