Point-contact investigation of CeRu2 in magnetic field

We have measured dV/dI(V) characteristics of point contacts between a CeRu2 polycrystal and normal metal (S-N contacts) as well as that of CeRu2 homoc ontacts (S-S contacts) in magnetic field. Special attention was paid to the region between the irreversible B* approximate to 3.5 T and the upper crit ical field B-c2 approximate to 6 T. The dV/dI(V) series of curves for S-N c ontacts demonstrate the suppression of the superconducting gap at about B*. Maximum Instead of minimum at zero-bias voltage develops when the held is increased above B*. The dV/dI(V) curves of S-S contacts show a nonzero resi stance at V = 0 and a gradual suppression of the zero-bias minimum in a mag netic held. The vortex dynamics and magnetic scattering are suggested as an explanation. (C) 1999 Elsevier Science B.V. All rights reserved.