The Interplay of Single Ion Anisotropy and Magnetic 3d-4f Interactions in V${}_2^{\mathrm{III}}$Ln${}_2^{\mathrm{III}}$ Butterfly Complexes

Abstract

Within the framework of 3d-4f molecular magnets, the most thoroughly investigated architecture is that of butterfly-shaped coordination clusters as it provides an ideal testbed to study fundamental magnetic interactions. Here, we report the synthesis and characterisation of a series of isostructural V${}_2^{\mathrm{III}}$Ln${}_2^{\mathrm{III}}$ butterfly complexes, where Ln = Y (1Y), Tb (2Tb), Dy (3Dy), Ho (4Ho), Er (5Er), Tm (6Tm), Yb (7Yb), which extends the previous study on isostructural butterflies with Cr${}^{\mathrm{III}}$, Mn${}^{\mathrm{III}}$ and Fe${}^{\mathrm{III}}$. In zero external field, compounds 2Tb, 3Dy and 4Ho show clear maxima in the out-of-phase component of the ac susceptibility whereas small magnetic fields are needed to suppress quantum tunneling in 6Tm. Combined high-field electron paramagnetic resonance spectroscopy and magnetisation measurements unambiguously reveal an easy-plane anisotropy of the V${}^{\mathrm{III}}$ ion and antiferromagnetic Ising-like 3d-4f exchange couplings. The strength of $J_{3d-4f}$ is shown to decrease upon variation of the 4f ion from Tb to Ho, while increasing antiferromagnetic interaction can be observed from Ho to Tm. The exact inverse chemical trend is found for the relative angle between the 3d and 4f main anisotropy axes, which highlights the important role of the lanthanide 4f electron distribution anisotropy for 3d-4f exchange.

arXiv comment11 pages, 9 figures

References in corpus (5)

• A complete ab initio view of Orbach and Raman spin-lattice relaxation in a Dysprosium coordination compound
• Origins of anomalously low Raman exponents in single-molecule magnets
• Origins of Slow Magnetic Relaxation in Single-Molecule Magnets
• Determination of the magnetic anisotropy axes of single-molecule magnets
• Anisotropy governed competition of magnetic phases in the honeycomb quantum magnet Na${}_3$Ni${}_2$SbO${}_6$ studied by dilatometry and high-frequency ESR

Cited by in corpus (1)

• Towards Understanding Prolate 4$f$ Monomers: Numerical Predictions and Experimental Validation of Electronic Properties and Slow Relaxation in a Muffin-shaped Er${}^{\mathrm{III}}$ Complex