A data/information storage and retrieval medium comprises: (a) a
substrate having a layer stack thereon, the layer stack including an
outer surface and comprising at least one magnetic or magneto-optical
("MO") recording layer; and (b) a thin film or layer of a lubricant on
the outer surface of the layer stack and comprised of a derivatized
perfluoropolyether-based material including at least one generally linear
perfluoropolyether chain and at least one phosphite
antioxidant/stabilizer moiety attached to at least one end of at least
one the chain.