  A study of path dependent effects in single crystals of CeRu2 and 2H-NbSe2
show that critical current density Jc of the vortex state depends on its
thermomagnetic history over a very large part of (H,T) parameter space. The
path dependence in Jc is absent above the peak position (i.e., H > Hp) of the
peak effect region, which we believe identifies the complete loss of order in
the vortex structure. The highly disordered FC state can be healed into a
relatively ordered vortex lattice by subjecting it to a large enough change in
dc field (few tens of Oe) or by shaking the FC state with sufficient ac field
(few Oe).
