Radiofrequency magnetoresistance of Fe/Cr superlattices

The rf magnetoresistance of Fe/Cr superlattices is studied for two orientat ions of the current: parallel and across the superlattice layers. A mutuall y single-valued correspondence is established between the relative magnetor esistance measured at dc current and the change in the transmission coeffic ient of electromagnetic waves in the magnetic field. When rf currents flow across the layers, the relative change in the signal amplitude is proportio nal to twice the change in the electrical resistance of the superlattice an d is of opposite sign. It is shown that the rf losses are determined by the surface resistance which is proportional to the superlattice thickness and inversely proportional to its conductivity. An equation is derived for the rf electric field distribution in the superlattice. It is established that when the thickness of the superlattice is small compared with the skin lay er depth, field and current components which penetrate through the entire s uperlattice exist. (C) 2000 MAIK "Nauka/Interperiodica".