Metallic quantum ferromagnets

A full understanding of long range ferromagnetic order in metallic systems reflects a variety of phenomena which are best understood in the context of quantum phase transitions (QPTs). This review presents experimental data on ferromagnetic QPTs in metals, confronting results with currently available theory. The coverage of clean materials, materials with varying degrees of disorder, and materials with phase diagrams is exhaustive, revealing a trend where the QPTs of clean systems driven by a control parameter are first order compared to more disordered systems where the QPTs are second order.