The CeMIn5 (M = Rh, Ir and Co) System and the Single Energy Scale Model of Metamagnetism

For a decade and a half, CeCoIn$_5$ and related alloys have served as a rich playground to explore the interplay between magnetism and unconventional superconductivity. Despite this extended study, the presence/absence of metamagnetism (MM) in this ternary system remains as an unresolved issue. Here we show that the linear and non-linear magnetic response in CeMIn$_5$ (M = Rh, Ir and Co) can be understood within the context of the recently proposed single energy scale (SES) model of MM. New measurements of the third-order susceptibility, $\chi_3$, in CeCoIn$_5$ are presented and together with the known systematics of the linear susceptibility in all three compounds, are shown to be consistent with the SES model. Predictions are made for the MM critical field in CeCoIn$_5$ and the fifth-order susceptibility, $\chi_5$.