Magnetic and crystallographic properties of Gd(Cu/sub 1-x/Ni/sub x/)2 and Gd(Cu/sub 1-x/Al/sub x/)2 intermetallic compounds

Magnetization, paramagnetic susceptibility, and temperature dependence of lattice parameters of Gd(Cu/sub 1-x/Ni/sub x/)2 (0 <= x <= 0.035) and Gd(Cu/sub 1-x/Al/sub x/)2 (0 <= x <= 0.07) intermetallic compounds with CeCu2-type structure have been studied in a wide range of temperatures. Below the ordering temperature anomalies in thermal expansion along the crystallographic axes a, b, and c enabled to distinguish between various types of magnetic arrangements. The Gd(Cu/sub 1-x/Ni/sub x/)2 system has two types of antiferromagnetic phases: AF1 (0 <= x <= 0.06) and AF2 (0.08 <= x <= 0.10), while for x >= 0.13 the system orders ferromagnetically. In the Gd(Cu/sub 1-x/Al/sub x/)2 system two magnetic phases AF1 and AF3 occur in the concentration regions 0 <= x <= 0.035 and 0.04 <= x <= 0.07, respectively. The obtained results are discussed in terms of the RKKY model via the changing conduction electron concentration. (author)