A Series of Lanthanide Compounds Constructed from Ln₈ Rings Exhibiting Large Magnetocaloric Effect and Interesting Luminescence

Abstract

A series of lanthanide compounds, [Ln₈(CH₂OHCH₂OH)₈(SO₄)₁₂]· m(C₂H₇N)· nH₂O (Ln = Gd (1), Sm (2), Tb (3), La (5), m = 2, n = 2; Ln = Eu (4), m = 0, n = 8), which contain Ln₈ rings by sulfate and glycol as the ligand have been synthesized and characterized. Besides, small organic amine and l-tartaric acid act as dual templating roles during the synthetic process. Magnetic investigation of compound 1 reveals the existence of weak antiferromagnetic interactions between Gd^III ions and the data of magnetic entropy change (-Δ S_m) is 36.86 J K^-1 kg^-1 (108.55 mJ cm^-3 K^-1) for Δ H = 7 T at 2.0 K, which is comparatively large among Gd^III based compounds. Additionally, because of the excellent luminescence properties of Sm^III, Tb^III, and Eu^III, compounds 2-4 were investigated.