A large cryogenic magnetocaloric effect exhibited at low field by a 3D ferromagnetically coupled Mn(II)-Gd(III) framework material

The large cryogenic magnetocaloric effect of a 3D oxydiacetate-bridged gadolinium-manganese MOF material, [Mn(H2O)(6)][MnGd(oda)(3)](2)center dot 6H(2)O (1), was evaluated by magnetization and heat capacity measurements. A maximum Delta S-m of 50.1 J kg(-1) K-1 for Delta H = 70 kG along with significant entropy change at lower field was found on account of the weak Mn center dot center dot center dot Gd ferromagnetic interactions and the small molecular mass. This suggests that 1 could be considered as a potential coolant for liquid helium temperature applications.