Fabrication and magnetic properties of electron beam lithography patterned arrays of single crystals

The fabrication method of arrays of iron squares separated by submicrometric distances is presented. The magnetic elements are defined on a single crystal Fe(001) film by electron beam lithography followed by a ion beam etching process. The obtained Fe squares present smooth surfaces and homogeneous sizes over areas as large as 500 μm x 500 μm as analyzed by scanning electron and atomic force microscopies. The lateral size of the squares have been varied in the range 1–10 μm in order to analyze the size dependence. The magnetic properties of the single crystalline squares have been studied by magnetooptical Kerr effect. The results reveal an important change in the hysteresis loops as the square dimensions are reduced below a threshold of 3 μm.