Metals near a magnetic instability

摘要

Zero-temperature magnetic phase transitions exhibit an abundance of nearly critical magnetic ???uctuations that allow to probe the traditional concepts of the metallic state. For the prototypical heavy-fermion compound, CeCu_6-e?‘￥Au_e?‘￥, a breakdown of the Fermi-liquid properties may be tuned by Au concentration, hydrostatic pressure, or magnetic ???eld. The d-electron weak itinerant ferromagnet ZrZn₂, on the other hand, was recently found to display superconductivity in coexistence with ferromagnetism.