Magnetic and transport properties of (Fe1-xNix)(2)P in view of KKR-CPA results

We present results of the electronic structure study for the solid solution (Fe1-xNix)(2)P (space group <P(6)over bar 2m>). The samples were synthesized for x = 0.0 up to 0.15. From the electrical conductivity measurements on these materials, it was verified that resistivity increases with increasing temperature up to the Curie point T-C and changes the slope at T-C decreasing when temperature is raised above T-C. To get insight into the possible origin of such observations, we carried out the Korringa-Kohn-Rostoker-coherent potential approximation electronic structure calculations for (Fe1-xNix)(2)P in the range of concentration x = 0.0 up to 1.0. It was found that alloying with Ni in Fe2P causes vanishing of spin band splitting and non-rigid band behaving of electronic valence states near the Fermi level. The polarization factor for electrons at E(F) changes in (Fe1-xNix)(2)P with increasing x, and interestingly, it reaches maximum at x = 0.1, closely to the concentration (x = 0.08), when the largest value of T-C and a kink in temperature dependent resistivity were detected.