Is CeNiSn the Kondo semiconductor?: break-junction data

Abstract

IVC characteristics as well as their derivatives were recorded for contacts on the base of CeNiSn, known as Kondo semiconductor, in the metallic and the tunnelling regime at temperatures between 0.1-8 K and in magnetic fields up to 8 T using mechanically controllable break junctions (MCBJ). It was found that CeNiSn behaves like a compound with typical metallic properties instead of the expected semiconducting behaviour. The main spectral feature is a pronounced zero-bias conductance minimum of about 10 meV width both for metallic and tunnel regime, which appears to be of magnetic nature. The experiments provide no clear-cut evidence for an energy (pseudo)gap in this compound.