Full compensation of oxygen vacancies in EuTiO3 (001) epitaxial thin film stabilized by a SrTiO3 surface protection layer

摘要

We fabricated highly insulating EuTiO3 (001) epitaxial thin films capped with SrTiO3 protection layers on SrTiO3 (001) substrates by combining pulsed laser deposition and post-annealing processes. The epitaxial SrTiO3 protection layer played a significant role in compensation of oxygen vacancies in the EuTiO3 thin films by preventing excess oxidation of the films and by “locking” the EuTiO3 perovskite structure in an epitaxial manner from the top during the air-annealing process. The obtained EuTiO3 thin films demonstrated an antiferromagnetic transition at 5.4 K, quantum paraelectricity down to ∼25 K, and a magnetoelectric coupling comparable to that of bulk EuTiO3.