Condensed Matter Seminars

A metamagnet (MM) is characterized by the sharp rise of the low-temperature magnetization at a critical field B_c. Other MM properties that become singular at T=0 and B= B_c include specific heats, magnetostriction, and sound velocities. Metamagnetism occurs in single molecules as well as in solids, and is not a phase transition in the classical sense; however, distinctive MM features are also seen at finite T for all B. We will present new data on macromolecules and heavy-fermion metals, such as UPt₃, and show how these systems are well described by a simple two-levels model, which appears to be applicable to all MMs, when suitably extended.