Fabrication and magnetic properties of new antiferromagnetic/ferromagnetic multilayers containing NiMn alloys

我们对Ni-Mn和NiMn/Co多层膜进行了研究，以开发出含有NiMn合金层的新型反铁磁-铁磁超晶格薄膜。通过在Au(111)织构薄膜上沉积Ni/Mn多层膜，获得了高质量的织构Ni/Mn超晶格。通过对它们的结构和磁学性质的分析，发现通过沉积“单层”厚的镍和锰可以得到反铁磁性的镍锰合金薄膜。通过改变“单层”范围内的沉积厚度比，可以在整个Ni-Mn系的浓度范围内制备面心立方合金薄膜。此外，我们还可以用上述方法制备由铁磁性Co(或Ni)和Ni-Mn合金层组成的NiMn/Co和NiMn/Ni超晶格薄膜。生长方向的晶体相干长度较长。在磁性方面，本研究制备的NiMn/Co超晶格与传统的溅射方法制备的NiMn/Co超晶格具有不同的磁性。

We have investigated Ni-Mn and NiMn/Co multilayered films to develop the new antiferromagnetic-ferromagnetic superlattice films containing NiMn alloy layers. By depositing the Ni/Mn multilayers on the Au(111) textured films, high quality textured Ni/Mn superlatttices are obtained. Based on their structural and magnetic characterizations, it was found that antiferromagnetic Ni-Mn alloy thin films can be obtained by depositing "mono-layer" thick Ni and Mn. Also by changing the ratio of the deposition thicknesses in the "mono-layer" range, it is possible to prepare fcc alloy films in the whole concentration range of Ni-Mn system. Furthermore, we could fabricate NiMn/Co and NiMn/Ni superlattice films counposed of ferromagnetic Co (or Ni) and Ni-Mn alloy layers prepared by the above method. The crystallographic coherence length in the growth direction is fairly long. Magnetically, NiMn/Co superlatttices prepared in this study show somewhat different properties from those prepared by the conventional sputtering method.