Epitaxial Thin Film Growth of Europium Dihydride

This paper reports the epitaxial growth of EuH2 thin films with an ω-scan full width at half-maximum of 0.07°, the smallest value for metal hydride thin films reported so far. The thin films were deposited on yttria-stabilized ZrO2 (111) substrates using reactive magnetron sputtering. The magnetization measurement showed that the saturation magnetization is ∼7 μB/Eu atom, indicating that the EuH x films are nearly stoichiometric (x ≈ 2.0) and that the Curie temperature is ∼20 K. The optical measurements showed a bandgap of ∼1.81 eV. These values are similar to those previously reported for bulk EuH2. This study paves the way for the application of metal hydrides in the field of electronics through the fabrication of high-quality metal hydride epitaxial thin films.