Magnetic Dilution of Bare‐Earth Aluminum Cubic Laves Phases RAL₂

Abstract

Abstract Curie temperatures and magnetizations are measured in the cubic Laves phases R x M 1− x Al 2 (R = Gd, Tb, Er and M = Y, La, Th). Upon dilution with Y or La a linear decrease of the Curie temperature, passing through zero for x = 0, is found. Dilution with Th results in an additional decrease of the Curie temperature. This effect is attributed to small changes of the Fermi wave‐vector. The results, as compared with Knight shifts, are discussed in terms of the Ruderman‐Kittel‐Kasuya‐Yosida theory. The exchange integral Γ is found to be of the order of −0.9 eV, and definitely negative.