  We report the successful growth of high-quality SrO films on highly-ordered
pyrolytic graphite (HOPG) and single-layer graphene by molecular beam epitaxy.
The SrO layers have (001) orientation as confirmed by x-ray diffraction (XRD)
while atomic force microscopy measurements show continuous pinhole-free films
having rms surface roughness of <1.5 {\AA}. Transport measurements of
exfoliated graphene after SrO deposition show a strong dependence between the
Dirac point and Sr oxidation. Subsequently, the SrO is leveraged as a buffer
layer for more complex oxide integration via the demonstration of (001)
oriented SrTiO3 grown atop a SrO/HOPG stack.
