A large cryogenic magnetocaloric effect exhibited at low field by a 3D ferromagnetically coupled Mn(ii)–Gd(iii) framework material

Abstract

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