Magnitocaloric effect in R$_3$Al$_2$ (R = Gd, Tb, Dy, Ho) alloys

Experimental studies of magnetic and magnetocaloric properties of polycrystalline alloys Gd$_3$Al$_2$, Tb$_3$Al$_2$, Dy$_3$Al$_2$, Ho$_3$Al$_2$ in external magnetic fields up to 3 Tesla have been carried out, and the change of the magnetic part of entropy in high magnetic fields generated by superconducting magnetic systems has been calculated. Magnetic measurements have shown that these compounds have low coercivity and reach saturation in low fields. It is found that the magnetocaloric effect in the studied compounds is observed in a wide temperature range, and for the intermetallides Gd$_3$Al$_2$, Tb3$_3$Al$_2$, Dy$_3$Al$_2$, Ho$_3$Al$_2$ has several existence regions comparable in the magnitude of the effect. The presence of several intervals of FEM existence is conditioned by a series of magnetic phase transitions in these ferrimagnetic compounds.