Giant magnetocaloric effect in GdAlO3 and a comparative study with GdMnO3

The magnetic properties and magnetocaloric effect of polycrystalline GdAlO₃ and GdMnO₃ have been investigated to assess their potential usage as magnetic refrigerants at cryogenic temperatures. These compounds undergo antiferromagnetic transitions at low temperatures which are associated with the giant magnetic entropy change effect (-\bigtriangleup {{S}_M} )  ∼40.9 J Kg · K^-1 under a field change of 0-9 T for GdAlO₃ while the moderate effect of 18 J Kg · K^-1 is observed for polycrystalline GdMnO₃. Though the relative cooling power of both the stated materials is similar however, the absence of magnetic and thermal hysteresis makes GdAlO₃ a more efficient magnetic refrigerant than GdMnO₃.