Slater-Pauling behavior within quaternary intermetallic borides of the Ti3Co5B2 structure-type

First-principles, density-functional studies of several intermetallic borides of the general type M₂M′Ru_5−nRh_nB₂ (n=0-5; M=Sc, Ti, Nb; M′=Fe, Co) show that the variation in saturation magnetic moment with valence-electron count follows a Slater-Pauling curve, with a maximum moment occurring typically at 66 valence electrons. The magnetic moments in these compounds occur primarily from the 3d electrons of the magnetically active M′ sites, with some contribution from the Ru/Rh sites via magnetic polarization. Electronic DOS curves reveal that a rigid-band approach is a reasonable approximation for the estimation of saturation moments and the analysis of orbital interactions in this family of complex borides. COHP analyses of the M′−M′ orbital interactions indicate optimized interactions in the minority spin states for Co-containing phases, but strong bonding interactions remaining in Fe-containing phases.