Large magnetoresistance in rare-earth based alloys

Abstract

The results of magnetoresistance (Δϱ/ϱ) measurements at low temperatures on the alloys, CeIr₂B₂, Pr_0.2R_0.8Cu₂Ge₂, Pr_0.2R_0.8Ni₂Si₂, and Pr_0.2R_0.8Cu₂Si₂ (R-La, Y), are reported. The Δϱ/ϱ of CeIr₂B₂ at 5 K (in the ferromagnetically ordered state) is large (-60%) at 70 kOe. In the case of Pr alloys, Δϱ/ϱ is positive thereby proving that the Kondo effect is absent in these alloys. One of the Pr alloys, Pr_0.2La_0.8Cu₂Si₂, also exhibits a large positive Δϱ/ϱ at 5 and 10 K about (28% at 70 kOe). Relevance of these findings to the current topic of interest on giant magnetoresistance will be pointed out.