Experimental and theoretical evidence that electrostatics governs easy-axis orientation in Dy^III-based molecular chains

Abstract

Magnetic slow relaxation is observed in a Dy(III)-based molecular chain and the magnetic easy-axis is determined via single-crystal magnetometry. Ab initio calculations confirm its orientation and highlight that the latter is governed neither by coordination polyhedron symmetry nor by the chain direction but rather by the single-ion electrostatic environment, a feature that is confirmed by a similar theoretical analysis on other Dy(III) chains.

Optimization of Magnetic Relaxation and Isotopic Enrichment in Dimeric DyIII Single‐Molecule Magnets

“…The substitution of the ancillary ligand does not have any significant influence on the orientation of the easy magnetic axes (Figure ); despite the different symmetry of the coordination environment, the easy magnetic axes are oriented almost strictly perpendicular to the Dy–Dy direction (calculated angles are 88.46° and 89.96° for Dy and DyPyNO , respectively). This agrees with the results of studies of similar compounds where easy magnetic‐axis orientation is not guided by coordination polyhedron symmetry but rather by global electrostatic considerations in the molecule , , , …”

Magnetic Slow Relaxation in a Metal–Organic Framework Made of Chains of Ferromagnetically Coupled Single‐Molecule Magnets

“…All coordinated oxygen atoms have been considered explicitly. In fact, some of us have previously demonstrated that a too‐simplified description of the neighboring environment of a given Dy III in a Dy chain can lead to a wrong description of the electrostatic features of the compound . This system can be then considered as a good model of the doped compound Y:Dy .…”

Relaxation Dynamics and Magnetic Anisotropy in a Low‐Symmetry DyIII Complex

“…[10,[18][19][20][21][22] Single-crystal magnetic measurements are still not very widespread, [23,24] even though they can cast light on magnetic anisotropy by providing access to the preferred orientations of magnetisation and to the degree of axiality of the low-lyingl evelso ft he J multiplet. [25][26][27] However,m ost crystal structures are comprised of symmetry-related but magnetically non-equivalent sites. In these cases, single-crystal magnetometry provides an averaged responsea nd deconvolution of the different contributions to anisotropy is often impossible.…”