Reversible switching between bidomain states by injection of current pulses in a magnetic wire with out-of-plane magnetization

The influence of current pulses on the domain structure of a 2 mu m wide wire composed of a soft out-of-plane magnetized magnetic material is studied by high spatial resolution nonintrusive magnetic imaging. The injection of current pulses (10(12) A/m(2)) leads to stable magnetic states composed of two domains with opposite magnetization direction separated by a domain wall parallel to the wire. The direction of the magnetization in the domains is reversed back and forth by applying successive current pulses with opposite polarity. The formation and control of the domain states by the current is attributed to the effect of the Oersted field, which is calculated to be large enough to induce the switching. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3058618]