Direct growth and electrical properties of YH₂ (111) epitaxial thin films on CaF₂ (111) and (001) substrates by reactive magnetron sputtering

YH₂ (111) epitaxial thin films with two and four rotational crystal domains were directly grown both on CaF₂ (111) and (001) substrates, respectively, at various growth temperature by reactive magnetron sputtering. The low growth temperature and the small number of crystal domains led to low resistivity in YH₂ (111) epitaxial thin films, probably attributed to less hydrogen deficiency in the films. Mobility as high as 14.3 cm²/Vs was obtained at 2 K possibly due to homogeneous hydrogen distribution.