Beschreibung:
<jats:p>The exchange anisotropy of pseudo-single crystalline Mn-Ir/Co-Fe bilayers with different crystallographic orientations, such as (110), (001), and (111), was investigated. As a result, we found that the unidirectional anisotropy constant JK strongly depends on the crystallographic orientation, while the critical thickness of the antiferromagnetic layer dAFcr is similarly ∼3 nm. As a notable result, the JK of the (110)-epitaxial bilayer with dAF=4 nm shows extra large value of 0.73 erg/cm2. The magnetic anisotropy of the Mn-Ir layer determined from the saturation torque amplitude was 8.5×105 erg/cm3 for the (110) bilayer, 5.0×104 erg/cm3 for the (001) bilayer, and 103–104 erg/cm3 for (111) bilayer, respectively. From the correlation between the exchange anisotropy and the magnetic anisotropy of the Mn-Ir layer, we conclude that the domain wall model is inadequate to explain these experimental results and the single spin model can do it qualitatively, assuming that the interfacial exchange coupling energy differs in the respective crystallographic orientation.</jats:p>