Superconductivity and magnetism in heavy-Fermion compounds

In this contribution we recall some of the early work devoted to Ce-based Kondo alloys which subsequently lead to thorough investigations on so-called Kondo-lattice systems like CeAl2, CeAl3 and CeCu2Si2, subsequently referred to as heavy-fermion metals. We then address the physical properties of the first heavy-fermion superconductor CeCu2Si2 and discuss the relationship of its superconductivity with both a spin-density-wave-type quantum critical point and a weak valence transition of Ce that occurs at high pressure. Finally, we introduce the isostructural Kondo-lattice system YbRh2Si2, displaying a novel type of quantum critical behavior which appears to be detrimental to superconductivity.