Current Density Dependence of Magnetoresistive Effect in NiFe Films

NiFe film samples with positive, negative and zero-valued magnetostrictions were formed by EB evaporation on quartz and BK-7 glass substrates, and the current density dependence of the MR effect was investigated. ¿R-H curves were shaped differently depending on the magnetostriction sign. Hk*, defined as the field value at which the change in resistivity ¿¿ is nearly zero, showed different dependences on the current density Js for different magnetostrictions; ¿¿m decreased with increasing Js for all samples. At certain current densities, both the ¿¿m and Hk* characteristics showed changes in slope, but the Js at which this occurred was different for the two substrates.