Soft x-ray magnetic circular dichroism study on Gd-doped EuO thin films

TL;DR

This study investigates Gd-doped EuO thin films, demonstrating how Gd doping enhances ferromagnetic properties and Curie temperature, with detailed characterization using soft x-ray magnetic circular dichroism.

Contribution

It provides a precise growth method for Gd-doped EuO films and reveals the ferromagnetic coupling and temperature enhancement due to Gd doping.

Findings

Curie temperature increases with Gd doping, reaching 170 K at 4% Gd.

Gd magnetic moments couple ferromagnetically with Eu.

Precise control of doping and oxygen stoichiometry achieved via molecular beam epitaxy.

Abstract

We report on the growth and characterization of ferromagnetic Gd-doped EuO thin films. We prepared samples with Gd concentrations up to 11% by means of molecular beam epitaxy under distillation conditions, which allows a very precise control of the doping concentration and oxygen stoichiometry. Using soft x-ray magnetic circular dichroism at the Eu and Gd M4,5 edges, we found that the Curie temperature ranged from 69 K for pure stoichiometric EuO to about 170 K for the film with the optimal Gd doping of around 4%. We also show that the Gd magnetic moment couples ferromagnetically to that of Eu.