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Updated: Sep 25, 2025
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
A new family of decanuclear Ln7Cr3 clusters exhibiting a magnetocaloric effect
Jia-Jia Yin1, Tian-Qi Lu1, Cheng Chen1
1Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Photoelectric Conversion Energy Materials and Devices Key Laboratory of Anhui Province, Anhui University Hefei 230601 China xyzheng@ahu.edu.cn.
Abstract:
Two dimeric Ln-Cr clusters with formula {Ln(H2O)8[Ln6Cr3(L)6(CH3COO)6(μ3-OH)12(H2O)12]}·(ClO4)6·xH2O (Ln = Gd, x = 35 for 1 and Ln = Dy, x = 45 for 2, HL = 2-pyrazinecarboxylic acid) were obtained by a ligand-controlled hydrolytic method with a mixed ligand system (2-pyrazinecarboxylic acid and acetate). Single crystal structure analysis showed that two trigonal bipyramids of [Gd3Cr2(μ3-OH)6]9+ worked as building blocks in constructing the metal-oxo cluster core of [Gd6Cr3(μ3-OH)12]15+ by sharing a common top - a Cr3+ ion. Additionally, compound 1 forms a three-dimensional framework with a one-dimensional nanopore channel along the a-axis through a hydrogen-bond interaction between the cationic cluster core and the free mononuclear cation [Gd(H2O)8]3+ and the π-bond interactions of the pyrazine groups on the two cationic cluster cores. Magnetic calculations indicated a weak ferromagnetic coupling interaction for Gd⋯Gd and Gd⋯Cr in compound 1, with its magnetic entropy change (-ΔS m) reaching 21.1 J kg-1 K-1 at 5 K, 7 T, while compound 2 displayed an obvious frequency-dependency at H dc = 2000 Oe.
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