Magnetization reversal of CrO ₂ nanomagnet arrays

Abstract

We report on fabrication techniques and the study of magnetic behavior of submicron-sized ferromagnetic CrO 2 arrays. Periodic rectangular arrays composed of circular dots with diameters ranging from 100 nm to 2 μm were fabricated by electron-beam lithography and reactive ion etching of CrO 2 epitaxial thin films. The magnetization reversal of the nanomagnet arrays was measured by the magneto-optical Kerr effect, with hysteresis characteristics found to be sensitively dependent on array details, film thickness, and its built-in strain, A rich variety of behaviors such as single domain, probable multidomain, as well as magnetization reorientation transition were observed, with magnetostatic interaction between the neighboring dots affecting the collective behavior of the nanomagnet arrays. © 2004 American Institute of Physics.