Spin-glass behavior of mechanically milled crystallineGdAl2

We report on the discovery of spin-glass behavior of a crystalline compound with a rather high content of the magnetic component, namely mechanically milled ${\mathrm{GdAl}}_2$ (mm-${\mathrm{GdAl}}_2$). Both ac and dc magnetic susceptibility measurements show a single transition from the paramagnetic to the spin-glass state below 65 K (${\mathit{T}}_{\mathit{f}}$), which is further confirmed by the observation of thermal irreversibility of the magnetization below ${\mathit{T}}_{\mathit{f}}$. Discovery of spin-glass behavior in mm-${\mathrm{GdAl}}_2$ is of significance since it not only represents a new class of spin-glass material but also demonstrates the use of mechanical milling as a novel technique to synthesize various new spin glasses.