POINT-CONTACT SPECTROSCOPY OF HEAVY-FERMION SYSTEMS

A review of heavy-fermion compounds investigated in their normal and s uperconducting states by point-contact spectroscopy is presented. The Joule heating appears to have a considerable influence on the conducti vity in metallic point contacts in both the normal and superconducting states. Nonetheless, some spectroscopic information can be obtained f rom the point-contact measurements, and Josephson effects are observed for certain heavy-fermion superconductors. We review in detail very r ecent development in this field, including experiments using mechanica lly controllable break junctions covering the regime from metallic con ductivity to truly vacuum tunnelling.