Reorientational magnetic transition in high-density arrays of single-domain dots

A theoretical study on the reorientational transition from in-plane to out-of-plane magnetized state is performed for two-dimensional magnetic dot arrays coupled by magnetostatic interaction. The square lattice of nanoscale cylindrical dots is considered with the assumptions that the dots are magnetically soft and they have uniform magnetization. The present study predicts that the interdot magnetostatic coupling determines the reorientation transition for close-packed arrays of such magnetic dots. Recent experimental results on the nanometer-scale single-domain dot arrays are discussed in light of the present calculation. (C) 2000 American Institute of Physics. [S0003-6951(00)02624-3].