Susceptibility of spin-fluctuation compounds in high magnetic fields

Abstract

The differential susceptibilities of the spin-fluctuation compounds ${\mathrm{TiBe}}_{2}$, ${\mathrm{UAl}}_{2}$, ${\mathrm{UCo}}_{2}$, and ${\mathrm{UPt}}_{3}$ have been measured at low temperatures as a function of magnetic field up to 40 T. A systematic relation is observed between the signs of the second derivatives of the susceptibility with respect to field and temperature. A characteristic field ${H}_{\mathrm{sf}}$ and a characteristic temperature ${T}_{\mathrm{sf}}$ are defined by the inflection points in the \ensuremath{\chi}(H) and \ensuremath{\chi}(T) curves, respectively. It turns out that ${\ensuremath{\mu}}_{B}$${H}_{\mathrm{sf}}$ is of the order of ${\mathrm{kT}}_{\mathrm{sf}}$.