Journal article

Slow Magnetic Relaxation in Lanthanoid Crown Ether Complexes: Interplay of Raman and Anomalous Phonon Bottleneck Processes

Elodie Rousset, Matteo Piccardo, Marie-Emmanuelle Boulon, Robert W Gable, Alessandro Soncini, Lorenzo Sorace, Colette Boskovic

CHEMISTRY-A EUROPEAN JOURNAL | WILEY-V C H VERLAG GMBH | Published : 2018

Abstract

The combination of lanthanoid nitrates with 18-crown-6 (18-c-6) and tetrahalocatecholate (X4 Cat2- , X=Cl, Br) ligands has afforded two compound series [Ln(18-c-6)(X4 Cat)(NO3 )]⋅MeCN (X=Cl, 1-Ln; X=Br, 2-Ln; Ln=La, Ce, Nd, Gd, Tb, Dy). The 18-c-6 ligands occupy equatorial positions of a distorted sphenocorona geometry, whereas the charged ligands occupy the axial positions. The analogues of both series with Ln=Ce, Nd, Tb and Dy exhibit out-of-phase ac magnetic susceptibility signals in the presence of an applied magnetic field, indicative of slow magnetization relaxation. When diluted into a diamagnetic La host to reduce dipolar interactions, the Dy analogue exhibits slow relaxation up to 2..

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Grants

Awarded by Australian Research Council


Awarded by Italian MIUR


Funding Acknowledgements

The authors thank Dr. Augustine Doronila and the TrACEES Platform of the University of Melbourne for their help with the ICP-OES analysis, Dr Nick Chilton for helpful discussions and Mr Robin Sanchez Arlt for preliminary synthetic work. Part of this research was undertaken on the MX1 beamline at the Australian Synchrotron (ANSTO), Victoria, Australia; the authors thank the beamline scientists for their valuable support and fruitful discussions. C.B. and A.S. acknowledge support from the Australian Research Council, Discovery Project Grant ID: DP1700034. This research was supported by use of the Nectar Research Cloud (https://nectar.org.au), a collaborative Australian research platform supported by the National Collaborative Research Infrastructure Strategy (NCRIS). L.S. and M.-E.B. acknowledge financial support from Italian MIUR through Project No. PRIN 2015-HYFSRT.