High exchange anisotropy and high blocking temperature in strongly textured NiFe(111)/FeMn(111) films

Strongly textured NiFe(111) underlayers, deposited by dc magnetron sputtering with applied substrate bias, are utilized to grow large, epitaxial grains of FeMn(111). These perfectly oriented (111) NiFe/FeMn bilayers exhibit the highest interfacial exchange anisotropy energy (0.17 erg/cm(2)), lowest coercivity (similar to 2 Oe) of the pinned layer, and highest blocking temperature (205 degrees C) ever reported, to the best of our knowledge. The relationship between the blocking temperature and the x-ray diffraction intensity of FeMn(111) indicates that the exchange interaction across the NiFe and FeMn interface is enhanced by the well-oriented, large, defect-free FeMn(111) crystals. (C) 1997 American Institute of Physics.