Pulsed laser deposition of SrRuO₃ thin-films: The role of the pulse repetition rate

SrRuO₃ thin-films were deposited with different pulse repetition rates, f_dep, epitaxially on vicinal SrTiO₃ substrates by means of pulsed laser deposition. The measurement of several physical properties (e.g., composition by means of X-ray photoelectron spectroscopy, the out-of-plane lattice parameter, the electric conductivity, and the Curie temperature) consistently reveals that an increase in laser repetition rate results in an increase in ruthenium deficiency in the films. By the same token, it is shown that when using low repetition rates, approaching a nearly stoichiometric cation ratio in SrRuO₃ becomes feasible. Based on these results, we propose a mechanism to explain the widely observed Ru deficiency of SrRuO₃ thin-films. Our findings demand these theoretical considerations to be based on kinetic rather than widely employed thermodynamic arguments.