Point-contact investigations of challenging superconductors: two-band MgB2, antiferromagnetic HoNi2B2C, heavy-fermion UPd2Al3, paramagnetic MgCNi3

摘要

An overview on recent efforts in point-contact (PC) spectroscopy of title superconductors is given. Distinct phonon features and crystalline-electric field effects are observed in PC spectra of HoNi2B2C. Results of study of superconducting (SC) gap and excess current versus temperature and magnetic field reflecting specific multi-band electronic structure in MgB2 are presented. The nature of the extremely nonlinear I(V) curves in the antiferromagnetic (AF) and SC state are elucidated for UPd2Al3 break junctions and MgCNi3 point contacts. (c) 2005 Elsevier B.V. All rights reserved.