Positive exchange bias in a Ni80Fe20/NixFe1−xO thin-film bilayer

We have measured positive exchange bias in a Ni80Fe20/NixFe1−xO thin-film nanocrystallite system. A series of solid solution NixFe1−xO 40 nm thick films capped with 25 nm thick Ni80Fe20 were deposited using a range of %O2/Ar bombardment energies (i.e. End-Hall voltages). Proper tuning of the deposition conditions results in a Ni80Fe20/NixFe1−xO (30%O2/Ar) based bilayer that exhibits a positive exchange bias loop shift of Hex∼60 Oe at 150 K.