SPIN-GLASS RESISTIVITY OF PSEUDOBINARY (TB, Y)AG AND (GD, Y)AG COMPOUNDS

In both series of compounds, spin-glass (SG) ordering is evidenced by the onset of magnetization irreversibilities at T(g), which in (Tb, Y)Ag is known to be accompanied by long-range antiferromagnetic (AFM) order with T(N) = T(g). Electrical resistivity (rho) versus temperature (T) data for each compound when corrected for the phonon contribution (derived from rho versus T for nonmagnetic YAg), show a constant high-T value (rho(HT)) down to T(g), where there is a rapid descent to a low-T residual value (rho0). From a reasonable estimate of the paramagnetic scattering contribution to rho(HT), the chemical-disorder component (rho(CD)) is determined. Assumed to be temperature independent, rho(CD) is then subtracted from rho0 to obtain the component of topological magnetic disorder (rho(MD)). In both TbxY1-xAg and GdxY1-xAg, the differences between the changes of rho(MD) and rho(CD) with decreasing x indicate a progressive development of SG order out of a gradual breakdown of AFM order.