Correlation between Electronic Configuration and Magnetic Stability in Dysprosium Single Atom Magnets
SEPTEMBER 27, 2021
Fabio Donati, Marina Pivetta, Christoph Wolf, Aparajita Singha, Christian Wäckerlin, Romana Baltic, Edgar Fernandes, Jean-Guillaume de Groot, Safa Lamia Ahmed, Luca Persichetti, Corneliu Nistor, Jan Dreiser, Alessandro Barla, Pietro Gambardella, Harald Brune, and Stefano Rusponi
Nano Letters (2021)
Description
Single atom magnets offer the possibility of magnetic information storage in the most fundamental unit of matter. Identifying the parameters that control the stability of their magnetic states is crucial to design novel quantum magnets with tailored properties. In this work we use X-ray absorption spectroscopy to show that the electronic configuration of dysprosium atoms on magnesium oxide (MgO) thin films can be tuned by the proximity of the metal Ag(100) substrate onto which the MgO films are grown. Increasing the MgO thickness from 2.5 to 9 monolayers induces a change in the dysprosium electronic configuration from 4f9 to 4f10. Hysteresis loops indicate long magnetic lifetimes for both configurations, however, with a different field-dependent magnetic stability. We combining these measurements with scanning tunneling microscopy, density functional theory, and multiplet calculations to unveil the role of the adsorption site and charge transfer to the substrate in determining the stability of quantum states in dysprosium single atom magnets.
Abstract
Single atom magnets offer the possibility of magnetic information storage in the most fundamental unit of matter. Identifying the parameters that control the stability of their magnetic states is crucial to design novel quantum magnets with tailored properties. Here, we use X-ray absorption spectroscopy to show that the electronic configuration of dysprosium atoms on MgO(100) thin films can be tuned by the proximity of the metal Ag(100) substrate onto which the MgO films are grown. Increasing the MgO thickness from 2.5 to 9 monolayers induces a change in the dysprosium electronic configuration from 4f9 to 4f10. Hysteresis loops indicate long magnetic lifetimes for both configurations, however, with a different field-dependent magnetic stability. Combining these measurements with scanning tunneling microscopy, density functional theory, and multiplet calculations unveils the role of the adsorption site and charge transfer to the substrate in determining the stability of quantum states in dysprosium single atom magnets.
