Effect of gadolinium doping on the electronic band structure of europium oxide

High quality films of EuO and Eu(0.96)Gd(0.04)O were grown on p-type Si(100) via pulsed laser deposition. X-ray-diffraction results show that the addition of Gd changes the growth texture from [001] to [111]. Angular-resolved photoemission spectroscopy reveals electron pockets around the X points in Gd-doped EuO, indicating that the band gap in EuO is indirect. Combined photoemission and inverse photoemission measurements show an apparent transition from n-type to p-type behavior, which is likely due to band bending near the polar (111) surface.