Gadolinium(III)-Hydroxy Ladders Trapped in Succinate Frameworks with Optimized Magnetocaloric Effect

Two kinds of inorganic gadolinium(III)-hydroxy ladders, [2xn] and [3xn], were successfully trapped in succinate (suc) coordination polymers, [Gd-2(OH)(2)(suc)(2)(H2O)](n) 2nH(2)O (1) and [Gd-6(OH)(8)(suc)(5)(H2O)(2)](n)4nH(2)O (2), respectively. Such coordination polymers could be regarded as alternating inorganic-organic hybrid materials with relatively high density. Magnetic and heat capacity studies reveal a large cryogenic magnetocaloric effect (MCE) in both compounds, namely (H=70kG) 42.8Jkg(-1)K(-1) for complex 1 and 48.0Jkg(-1)K(-1) for complex 2. The effect of the high density is evident, which gives very large volumetric MCEs up to 120 and 144mJcm(-3)K(-1) for complexes 1 and 2, respectively.