Pressure and Substitution Effects on Transport and Magnetic Properties of Y1-xRxCo2Systems with Static Magnetic Disorder

Abstract

The electrical resistivity and thermopower of light- and heavy-rare-earth-based pseudo-binary Y1-xRxCo2 (R = Nd, Gd, and Tb) alloys are measured at temperatures from 2 to 300 K under pressures up to 3.5 GPa. The resistivity and thermopower of Y1-xRxCo2 show unusual large variations with atomic substitution and pressure in the range of x<xm, where an inhomogeneous magnetization of the Co 3d electron subsystem is observed. These results indicate that the low-temperature transport properties of Y1-xNdxCo2, as well as of Y1-xR\text{HCo2 (R\text{H = heavy rare earth) alloys, are related to conduction electron scattering due to the static magnetic disorder in the itinerant Co 3d electron subsystem. We found that there is a universal relationship between \(\mathrm{d}\ln T_{\text{C}}/\mathrm{d}P\) and \(x/x_{\text{m}}\) in Y1-xRxCo2 alloys, where \(x_{\text{m}}\) is the boundary composition, which separates the alloy phase diagram into regions with uniform and nonuniform magnetizations of the Co-3d electron subsy...