Magnetic anisotropy in surface-supported single-ion lanthanide complexes

TL;DR

This study investigates the magnetic anisotropy of surface-supported single-ion lanthanide complexes, revealing how molecular distortion influences magnetic orientation and electron coupling, with implications for atomic-scale spintronics.

Contribution

It demonstrates how surface deposition causes molecular distortion in Dy(tta)$_3$ complexes, affecting their magnetic anisotropy and electron coupling properties.

Findings

Molecular distortion induces a specific crystal field symmetry.

The complexes exhibit an easy-axis magnetization in the ligand plane.

Tunneling electrons show weak coupling to spin excitations.

Abstract

Single-ion lanthanide-organic complexes can provide stable magnetic moments with well-defined orientation for spintronic applications on the atomic level. Here, we show by a combined experimental approach of scanning tunneling microscopy and X-ray absorption spectroscopy that dysprosium-tris(1,1,1-trifluoro-4-(2-thienyl)-2,4butanedionate) (Dy(tta)$_3$) complexes deposited on a Au(111) surface undergo a molecular distortion, resulting in distinct crystal field symmetry imposed on the Dy ion. This leads to an easy-axis magnetization direction in the ligand plane. Furthermore, we show that tunneling electrons hardly couple to the spin excitations, which we ascribe to the shielded nature of the $4f$ electrons.