Point-contact spectroscopy of the nickel borocarbide superconductors RNi2B2C (R=Y, Dy, Ho, Er, Tm, Lu)

Abstract

An overview of the recent efforts in point-contact (PC) spectroscopy of the nickel borocarbide superconductors RNi2B2C in the normal and superconducting (SC) state is given. The results of measurements of the PC electron- boson(phonon) interaction spectral function are presented. Phonon maxima and crystalline-electric-field (CEF) excitations are observed in the PC spectra of compounds with R=Dy, Ho, Er and Tm, while for R=Y a dominant phonon maximum around 12 meV is characteristic. Additionally, non-phonon and non-CEF maxima are observed near 3 meV in R=Ho and near 6 meV in R=Dy. Directional PC study of the SC gap gives evidence for the multi-band nature of superconductivity in R=Y, Lu. At low temperature the SC gap in R=Ho exhibits a standard single-band BCS-like dependence, which vanishes above T_c^*= 5.6K< T_c=8.5K, where a specifc magnetic ordering starts to play a role. For R=Tm (T_c=10.5 K) a decrease of the SC gap is observed below 5 K.

7 figs, 4 pages, presented on M2S-HTSC Conference, July 9-14, 2006, Dresden

References in corpus (4)

• Upper critical field pecularities of superconducting YNi2B2C and LuNi2B2C
• Weak inter-band coupling in Mg${}^{10}$B${}_2$: a specific heat analysis
• Point-contact spectroscopy of the borocarbide superconductor YNi2B2C
• Point-contact investigations of challenging superconductors: two-band MgB2, antiferromagnetic HoNi2B2C, heavy fermion UPd2Al3, paramagnetic MgCNi3

Cited by in corpus (6)

• Probing multiband superconductivity by point-contact spectroscopy
• Superconducting order parameter in nonmagnetic borocarbides RNi${}_2$B${}_2$C (R=Y, Lu) probed by point-contact Andreev reflection spectroscopy
• Peculiarities of the superconducting gaps and the electron-boson interaction in TmNi2B2C as seen by point-contact spectroscopy
• Two-gap superconductivity: interband interaction in the role of external field
• The Superconducting Gap Behavior in the Antiferromagnetic Nickel-Borocarbide Compounds RNi2B2C (R=Dy, Ho, Er, Tm) Studied by Point-Contacts Spectroscopy
• Two-gap superconductivity in the noncentrosymmetric La${}_3$Se${}_4$ compound