Enhanced spin-valve giant magneto-resistance in non-exchange biased sandwich films

A large giant magnetoresistance (GMR) value of 7.5% has been measured in si mple NiFeCo(1)/Cu/NiFeCo(2) sandwich films grown on a 30 Angstrom Cr seed l ayer. This spin-valve GMR effect is consistent with the differential switch ing of the two NiFeCo layers due to an enhanced coercivity of the NiFeCo(1) layer grown on the Cr seed layer. A change in growth texture of the NiFeCo (1) layer from fee (111) to bce (110) crystallographic orientation leads to an increase in magnetic anisotropy and an enhancement in coercivity, The G MR value increases to 8.7% when a thin CoFe interfacial enhancing layer is incorporated. Further enhancement in GMR values up to 14% is seen in the sa ndwich films by nano-oxide layer formation. The specular reflection at the oxide/magnetic layer interface further extends the mean free path of spin-p olarized electrons.