Magnetic ordering in YGd alloys

We present magnetization and resistivity measurements on single crystals of yttrium doped with small concentrations of gadolinium (c=1, 2, and 3 at. %). The low-field susceptibility exhibits a spin-glass-like sharp cusp for the magnetic field along the c axis. However, there is no irreversible behavior below the temperature of the cusp, which rules out the existence of a spin-glass state. Moreover, our magnetization measurements show up a spin-flop transition for H in the basal plane. The existence of a long-range ordering is confirmed by our resistivity measurements. The resistivity parallel to the c axis exhibits a maximum just below the ordering temperature, which is reminiscent of the superzone effects observed in many rare-earth metals. The antiferro- magneticlike properties of the YGd alloys contrast with the spin-glass behavior observed in other Y–rare-earth alloys at similar concentrations.