Scaling magnetic and magnetocaloric properties of GdAl${}_2$ by erbium substitution

We report on magnetic and magnetocaloric properties of polycrystalline Gd$_{100-x}$Er$_x$Al$_2$ ($x = 0; 50$). It was found that substitution of Gd for Er does not affect considerably the value of the isothermal magnetic entropy change, which is equal to $\Delta S_M = –5.0\ J/(\text{kg} \times \text{K})$ at $T_C = 163$ K for GdAl$_2$ and $\Delta S_M = -4.9\ J/(\text{kg}\times \text{K})$ at $T_C = 97 K$ for Gd$_{0.5}$Er$_{0.5}$Al$_2$ (for the magnetic field change of $3$ T). However, in the Gd$_{0.5}$Er$_{0.5}$Al$_2$ alloy, a large MCE is observed in a wide temperature range $\Delta T = 66$ K, which makes this materials promising for a magnetic cooling technology at low temperatures.