Lanthanide magnetic anisotropy

Some gadolinium-based MOF have also revealed the peculiar dynamics of the magnetization with the appearance of the out-of-phase component of the dynamic magnetization in presence of an applied static magnetic field. This behaviour, which is reminiscent of the field-induced slow relaxation that characterize many lanthanide-based SMMs, is however not related to the magnetic anisotropy, which is vanishingly small in most Gd3+ systems. 

Magnetic measurements on oriented single crystals are the ideal technique for direct observation of the magnetic anisotropy. Therefore at a first glance, it may appear surprising that relatively few single-crystal studies on lanthanide... 

Control of the Magnetic Anisotropy of Lanthanide Ions Chemical Design of Spin Qubits 7.3.2.1 Mononuclear Single Molecule Magnets... 

For lanthanides other than Gd(III), the magnetic anisotropy still depends on the the local coordination environment it determines which crystal field anisotropy terms in Equation 7.2 are allowed by symmetry, the rest simply vanish. However,... 

The crystal field does, however, have a dramatic effect on the magnetic anisotropy of lanthanide complexes. For complexes of less than cubic symmetry the three principal values of the susceptibility tensor are unequal. For uniaxial symmetry, Xx — Xy Xz and for biaxial symmetry Xx Xy Xz- Very extensive studies632-640 have been carried out on the single crystal susceptibilities of the D3d lanthanide hexakis(antipyrene) triiodides over the temperature range 80-300 K, and crystal field parameters were obtained. This crystal field-induced anisotropy is responsible for the effectiveness of lanthanide complexes as NMR shift reagents, and single crystal anisotropies of lanthanide complexes have been determined in this connection also.563... 

Analogously, the pseudocontact shifts were used to refine the solution structure of the Ce(III), Dy(III) and Yb(III) derivatives of monolanthanide-substituted Calbindin D9k. Since the three lanthanides span a wide range of magnetic anisotropies, the refinement was effective in shells from the metal of 5—15 A for Ce(III), 9-25 A for Yb(III), 13-40 A for Dy(III), as useful pseudocontact shifts were observed in these shells (Fig. 5.59) [167]. Therefore, by using different lanthanides it was possible to enlighten shells at variable distances from the metal itself. 

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