Abstract:

Two lanthanide cluster-based metal-organic frameworks of {[Gd₇(OH)₈(HOCH₂COO)₈(H₂O)₃]·Cl₅·3H₂O}_n(Ln=Gd(1), Dy(2)) were obtained by solvothermal reaction. The magnetic studies indicate that compound 1 exhibits a large magnetocalotic effect(MCE) values of 44.4 J/(kg·K) at 2 K and ΔH=7 T and compound 2 displays obvious frequency dependence(H_dc=0) which suggests that compound 2 shows slow relaxation. In addition, the results of powder diffraction reveals that compounds 1 and 2 display very high chemical stability, which can be stable in acid/base solution of pH=1~14 and boiling water. These results indicate that the lanthanide cluster-based metal-organic frameworks have the potential application in the low-temperature refrigeration.

Key words: lanthanide organic-metal frameworks, magnetocalotic effect, frequency dependence, chemical stability