Origin of RHEED intensity oscillations during the growth of (Y,Dy)${\mathrm{Ba}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{7\mathrm{-}\mathit{x}}$ thin films

We propose a mechanism for the origin of RHEED intensity oscillations during the growth of (Y,Dy)${\mathrm{Ba}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_7$ thin films. Surface relaxation and RHEED intensity recovery observed during the growth of these materials are ascribed predominantly to the diffusion of already formed (Y,Dy)${\mathrm{Ba}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_7$ units rather than to the chemical reaction of the constituents to form a unit cell. The validity of the model is demonstrated by comparing the surface step densities determined from results of Monte Carlo simulations with RHEED intensity oscillations observed during pulsed laser deposition.