Evidence for canted antiferromagnetism in lightly doped (formula presented)

We present magnetization measurements on lightly doped (formula presented) single crystals with (formula presented) in external fields up to 14 T at temperatures between 4.2 and 180 K. In contrast to the ferromagnetic behavior which is found for (formula presented) the samples with (formula presented) and (formula presented) exhibit a pronounced hysteresis and a constant high-field susceptibility. By analyzing this particular behavior we can rule out a phase separation into ferromagnetic and antiferromagnetic regions. On the other hand, a model of a canted antiferromagnet can account for the main experimental features.