Epitaxial and stoichiometric La_0.5Sr_0.5CoO₃ thin films with a mobile pulsed laser deposition system

Sharath Rameshbabu, Daniele Pergolesi, Arnold Müller, Christof Vockenhuber, Thomas Lippert and Davide Bleiner;

Abstract:

A modular pulsed laser deposition (PLD) system was built and validated on the epitaxial growth of La_0.5Sr_0.5CoO₃ (LSCO) thin films. The LSCO growth was compared using both a second harmonic Nd: YAG (λ = 532 nm) laser and a excimer KrF (λ = 248 nm) laser. Epitaxial growth was confirmed in both cases. Crystallographic analysis confirmed epitaxial growth with in-plane tensile strain, consistent with the 1.7% lattice mismatch between LSCO and SrTiO₃ (STO) substrates. In-plane and out-of-plane lattice parameters were determined from asymmetric reciprocal space map (RSM). The in-plane parameter in both films was determined to be 3.91 Å, while the out-of-plane parameter was ca. 3.78 Å. The ¹⁶O resonance Rutherford Backscattering (RBS) measurements validated the stoichiometric growth of the thin films. The films grown using the Nd: YAG and excimer lasers exhibited comparable thicknesses.