Magnetic interactions in nanometer-scale particle arrays grown onto permalloy films

The magnetic interactions in arrays of nanometer-scale ferromagnetic iron p articles enhanced by direct growth onto thin permalloy films were investiga ted. The magnetic measurements [Hall magnetometry up to 100 K and variable field MFM (magnetic force microscopy) at room temperature] showed that the magnetization behavior of the permalloy was strongly influenced by the pres ence of the small (similar to 13 nm in diameter) particles. The mean values of the particles' switching fields coincided with those for noninteracting particles. The switching field distribution of the iron particles, however , was considerably broadened by their interactions. These results for stron gly interacting small particles exemplify the magnetization behavior of eve r smaller and more dense magnetic storage media. (C) 2000 American Institut e of Physics. [S0021-8979(00)61208-2].