  We report structural and magnetic properties of multilayers composed of thin
layers of the half metallic ferromagnetic Heusler compound Co2MnGe and layers
of Au, Cr and the Heusler compound Cu2MnAl. The hysteresis loops measured at
low temperatures reveal the existence of an exchange bias field HEB in all of
these multilayers. For the [Co2MnGe/Au] multilayer system HEB is largest
reaching up to 1 kOe at a temperature of 2 K. We characterize the exchange bias
phenomenon in detail and show that it originates from a spin glass type of
magnetic order for a thin interlayer at the interfaces. We discuss the results
in the light of different models proposed for the explanation of the exchange
bias effect.
