Magnetic properties of the integrated (Fe, M)3O4 (M=Mn and Zn) nano-array structures in large area prepared by Nanoimprint lithography with Mo lift-off technique

The highly integrated epitaxial nano-structures of ferro/ferrimagnetic (Fe,M)3O4 (M=Mn and Zn) were fabricated in large area (2×2 mm2) using Nanoimprint lithography with the Mo lift-off technique. This technique allows us to construct the scalable nano-structures of the epitaxial metal oxide on one substrate in a lump, and realizes quantitative physical property measurement as a scalable system. The dependence of magnetic property on the dot size was obtained quantitatively by a SQUID magnetometer. The coercive field (HC)(HC) of Fe2.1Zn0.9O4 nano-dot was systematically enhanced up to 4.8 times larger than that of the continuous film whereas HCHC of Fe2.5Mn0.5O4 nano-dot was fairly decreased. Dependence of magnetism on temperature suggested that the size dependence of HCHC originates from an isolated magnetic state in cluster glass nature.