MODELING OF THE ELECTRICAL-RESISTIVITY OF FERROMAGNETIC AND PARAMAGNETIC INTERMETALLIC COMPOUNDS

The temperature dependence of the electrical resistivity of some magnetic intermetallic compounds is analysed using a model which takes into account the changes in the electronic structure with the variation of the long-range order, neglecting chemical and magnetic short-range order (SRO) effects. The values of atomic and magnetic long-range order (LRO) parameters are obtained using a magnetic-cluster variation method (CVM) approach with the interaction parameters fitted to the equilibrium phase diagrams. The three principal components of the resistivity, namely the chemical disorder, the magnetic disorder, and the electron-phonon scattering contributions, are reproduced well for several paramagnetic (NiPt, Feo.7Al0.3) and ferromagnetic (CoPt, Co0.3Pt0.7) compounds. Our analysis indicates an important change in the electronic structure with the variation of the LRO parameter, this effect being very pronounced in Feo.7Al0.3.