Peak effect in CeRu 2 : History dependence and supercooling

We present experimental results on single crystal ${\mathrm{CeRu}}_{2}$ showing that the extent of the history dependence of peak effect depends on the path followed in the space of field (H) and temperature $(T).$ The $(H,T)$ regime over which the history effect is observed is larger if the vortex lattice is prepared by lowering T from above ${T}_{C}$ in constant H, i.e., by field cooling. We compare this history effect with the very recently reported history dependence of peak effect in detwinned single crystals of YBaCuO and $2\mathrm{H}\ensuremath{-}{\mathrm{NbSe}}_{2},$ highlighting the similarities and differences. We discuss the possibility of a first-order vortex solid-solid transition in ${\mathrm{CeRu}}_{2}$ within the realm of recent theoretical developments in the field of vortex matter.