Thermally activated magnetization reversal in nanometer-size iron particles - art. no. 012402

Arrays of nanometer-scale iron particles were fabricated by scanning tunnel ing microscopy assisted chemical vapor deposition. This allowed precise con trol over the particles' dimensions (diameters down to 9 nm) and their arra ngement. The temperature dependence of the switching fields of these elonga ted particles revealed a thermally activated nucleation/propagation type of magnetization reversal even for our smallest particles. Improved high sens itivity Hall magnetometry allowed magnetic viscosity measurements which con firmed an activation volume much smaller than the particle size.