Magnetic micropatterning of FeNi/FeMn exchange bias bilayers by ion irradiation

Ion irradiation is an excellent tool to modify magnetic properties on the s ubmicrometer scale, without modification of the sample topography. We utili ze this effect to magnetically pattern exchange bias double layers using re sist masks patterned by electron-beam lithography. Ion irradiation through the masks leads to a lateral modification of the magnetization reversal beh avior and allows one to study the magnetization reversal as a function of t he exchange bias field strength on a single sample. Results are presented o n the macroscopic and microscopic magnetization reversal using the magneto- optic Kerr effect and magnetic force microscopy, respectively. (C) 2001 Ame rican Institute of Physics.