Common low-temperature magnetic anomalies in oxygen-doped heavy rare-earth cuprates R 2CuO 4 (R=Tb,Dy,Ho, and Tm)

Abstract

We have studied the low-temperature magnetic properties of oxygen-doped heavy rare-earth cuprates R 2CuO 4 (R=Tb,Dy,Ho, and Tm). Two low temperature anomalies, one at ∼ 28 K, the other one located at 5 to 17 K, were found. The higher temperature anomaly is a common behavior of all oxygen-doped T′ - R 2CuO 4 cuprates. We assigned it to the formation of ferromagnetic clusters in CuO 2 planes. The low temperature anomaly may correspond to the coupling of the above anomaly to the rare-earth moment.