Magnetic properties of R2BaCuO5 (R=Y, Gd, Yb)

Abstract SQUID and ESR measurements were performed for R 2 BaCuO 5 (R=Y, Gd, Yb) in a temperature range from 5 to 80 K. The magnetic susceptibility increased suddenly with decreasing temperature from the Neel point of 15 K in Y 2 BaCuO 5 . In Gd 2 BaCuO 5 and Yb 2 BaCuO 5 , the magnetic susceptibility of Cu 2+ similarly increased suddenly below 18 K. On the other hand, the susceptibility of Gd 3+ and Yb 3+ decreased just below 10–12 K, which was the Neel temperature in Gd 2 BaCuO 5 and Yb 2 BaCuO 5 . A weak ferromagnetism appears below 18 K in the Cu-sublattice, and the magnetic ordering in the Cu-sublattice may induce the antiferromagnetic transition in the Gd- and Yb-sublattice.