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Updated: Mar 22, 2026
High Resolution Physical Characterization of Single Metallic Nanoparticles
Published on: June 28, 2019
Single-Molecule Magnet Behavior of Individual Polyoxometalate Molecules Incorporated within Biopolymer or
William Salomon1, Yanhua Lan2, Eric Rivière3
1Institut Lavoisier de Versailles, UMR CNRS 8180, Université Paris Saclay, Université de Versailles St-Quentin en Yvelines, 45 Avenue des Etats-Unis, 78035, Versailles cedex, France.
Abstract:
The chemically and structurally highly stable polyoxometalate (POM) single-molecule magnet (SMM) [(FeW9 O34 )2 Fe4 (H2 O)2 ](10-) (Fe6 W18 ) has been incorporated by direct or post-synthetic approaches into a biopolymer gelatin (Gel) matrix and two crystalline metal-organic frameworks (MOFs), including one diamagnetic (UiO-67) and one magnetic (MIL-101(Cr)). Integrity of the POM in the Fe6 W18 @Gel, Fe6 W18 @UiO-67 and Fe6 W18 @MIL-101(Cr) composites was confirmed by a set of complementary techniques. Magnetic studies indicate that the POMs are magnetically well isolated. Remarkably, in Fe6 W18 @Gel, the SMM properties of the embedded molecules are close to those of the crystals, with clear quantum tunneling steps in the hysteresis loops. For the Fe6 W18 @UiO-67 composite, the molecules retain their SMM properties, the energy barrier being slightly reduced in comparison to the crystalline material and the molecules exhibiting a tunneling rate of magnetization significantly faster than for Fe6 W18 @Gel. When Fe6 W18 is introduced into MIL-101(Cr), the width of the hysteresis loops is drastically reduced and the quantum tunneling steps are smeared out because of the magnetic interactions between the antiferromagnetic matrix and the SMM guest molecules.
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