  The exchange bias of the soft ferromagnet mu-metal, Ni77Fe14Cu5Mo4, with the
metallic antiferromagnet Fe50Mn50 has been studied as a function of ferromagnet
thickness and buffer layer material. Mu-metal exhibits classic exchange bias
behavior: the exchange bias (HEB) and coercive fields scale inversely with the
ferromagnet's thickness, with HEB varying as the cosine of the in-plane applied
field angle. While the exchange bias, coercivity, and exchange energy are
greatest when the buffer layer material is (111) oriented Cu, amorphous Ta
buffers allow the mu-metal to retain more of its soft magnetic character. The
ability to preserve soft ferromagnetic behavior in an exchange biased
heterostructure may be useful for low field sensing and other device
applications.
