Growth of exchange-biased MnPd/Fe bilayers

The growth of exchange-biased MnPd/Fe bilayers has been investigated using x-ray diffraction. The bilayers were deposited on MgO(001) substrates in an ultrahigh-vacuum ion-beam sputter system. It was found that the orientation of the MnPd unit cell and the crystalline quality could be controlled as a function of the deposition temperature. Twinned a-axis oriented MnPd films are obtained below 100 degreesC while single-crystalline c-axis films are obtained above 450 degreesC. Intermediate temperatures yield a mixture of both orientations with a poor crystalline quality. Moreover, the interface quality depends strongly on the deposition temperature and also the order in which MnPd and Fe are deposited. The results clearly show that interdiffusion is initiated at the Fe/MnPd interface at a lower temperature as compared to the MnPd/Fe interface. The close relationship between the structural and magnetic properties is also discussed. (C) 2004 American Institute of Physics.