Unusual magnetic and transport properties in naturally layered intermetallic compounds R2Ni2Pb (R = Gd, Tb and Y)

We studied the magnetic and transport properties of the orthorhombic compounds R2Ni2Pb (R = Gd, Tb and Y) by means of magnetization and magnetoresistivity measurements. These compounds form a new family of naturally layered intermetallics with a magnetic structure that can be tailored by changing the rare-earth element. Our results show a subtle interdependence between the magnetoresistance and the metatnagnetic behavior in these systems. We attribute such anomalous behavior to the layered structure of the compounds, and to the intricacies introduced by the complex magnetic structure of rare earths. First-principles density-functional calculations for the electronic structure of Y2Ni2Pb are presented to support this idea. (C) 2003 Elsevier B.V. All rights reserved.