Adsorption controlled molecular beam epitaxy of rubidium barium bismuth oxide

Measurements of the sticking coefficients for rubidium, barium, and bismuth have been made during molecular beam epitaxy of (Rb,Ba)BiO3 on MgO. This simple cubic perovskite is a high temperature superconductor for Rb fractions between 0.4 and 0.5. The dependence of the sticking coefficients on substrate temperature, oxygen plasma conditions, and on incident flux composition indicate that in a narrow region of flux compositions, adsorption, and desorption rates of bismuth and rubidium will control the stoichiometry of the film.