Calculated and measured normal state resistivity of 19-filament MgB2/Ti/Cu/stainless steel wire

This work describes the resistivity evolution of filamentary MgB 2 /Ti/Cu/stainless steel wire under the influence of solid state interaction between individual elements of the composite. The experimental samples were heat treated at temperatures of 650–850 °C and the properties of the interface layers have been estimated on the basis of solid state growth of intermetallic compounds formed by diffusion. The corresponding composite resistivity along the longitudinal direction was calculated using a model represented by an equivalent parallel circuit of n resistors. The temperature dependence of the electrical resistivity was measured for the experimental sample, a specially prepared Cu/Ti couple, and all individual metallic components used in the sample, using a cryogen-free characterization system. Very good agreement between the calculated ρ( T ) dependences and the experimentally measured resistivity of 19-filament MgB 2 /Ti/Cu/stainless steel wire has been obtained.