Magnetization reversal in an ordered array of ferromagnetic nanodots

The magnetization reversal in an array of Fe nanodots etched from the continuous iron film by a focused Ga$^+$ ion beam has been studied. The size of the dots is 600 nm, and the interdot distances are equal to 3.8 $\mu$m, 900 nm, and 700 nm. The energy of the dipole-dipole interaction between the nanodots is estimated for arrays with different periods. It is demonstrated that the mechanisms of magnetization reversal are different in arrays of nanodots with strong and negligible dipole-dipole interactions.