Theory of itinerant electron metamagnetism

We propose a phenomenological picture for the mechanism of the metamagnetic transition often observed in intermetallic alloy compounds near the paramagnetic side of the ferromagnetic instabilities such as YCo 2 with Al doping. The present treatment assumes the magnetization process is described in terms of the spin fluctuation spectrum, in clear contrast with the previous approaches based on the Hartree-Fock approximation assuming the fine structure of the density of states curve around the Fermi energy.