  The exchange bias effect is commonly used to shift the coercive field of a
ferromagnet. This technique is crucial for the use of magnetic tunnel junctions
as logic or memory devices. Therefore, an independent switching of the two
ferromagnetic electrodes is necessary to guarantee a reliable readout. Here, we
demonstrate that the intrinsic exchange bias effect of Ni-Mn-Sn can be used to
apply a unidirectional anisotropy to magnetic tunnel junctions. For this, we
use epitaxial Ni-Mn-Sn films as pinning layers for microfabricated
CoFeB/MgO/CoFeB magnetic tunnel junctions. We compare the exchange bias field
($H_{\text{EB}}$) measured after field cooling in $-10$\,kOe external field by
magnetization measurements with $H_{\text{EB}}$ obtained from tunnel
magnetoresistance measurements. Consistent for both methods we find an exchange
bias of about $H_{\text{EB}}=130$\,Oe at 10\,K, which decreases with increasing
temperature and vanishes above 70\,K.
