Pressure Dependence of the Magnetic Interactions in Eu_xYb_1−x Alloy

Abstract

Ac magnetic susceptibility χ, magnetization σ and electrical resistivity ρ of Eu_xYb_1−x were measured at high pressure up to 15 kbar in the temperature range from 1.6 K to 300 K. For x=0.20, which has two transition points from paramagnetic to ferromagnetic state, and from ferromagnetic to spin glass like state, T_c=26 K and T_t=2.3 K, respectively at ambient pressure, T_c decreases drastically and T_t increases with increasing pressure p, at the rates of ΔT_c⁄Δp=−9.5 K/kbar and ΔT_t⁄Δp=+1.7 K/kbar respectively and σ at 4.2 K decreases drastically with increasing p, while the transition point from paramagnetic to spin glass like state, T_g, which appears above p=2.5 kbar is independent on p. From the ρ data of x=0.025 and 0.35, the remarkable transition to semiconducting state with increasing p is indicated.