Growth of crystalline doped β-alumina thin films by laser ablation

Abstract

Crystalline thin films of sodium β-alumina and β-aluminogallate for optical applications have been deposited onto various single-crystal substrates by the pulsed laser deposition technique. Films with a smooth surface morphology were obtained by using Cr-doped targets. Despite Na loss in the films with respect to the target composition, the β-alumina crystalline phase was grown at elevated temperature (700–800 °C), and highly textured (00l) films were obtained, whatever the substrates: MgO, ZrO ₂ , Al ₂ O ₃ or Si. The optical properties were studied by measuring the refractive index of the films and performing the emission spectrum of the Cr ³⁺ ions, providing results very similar to those of the bulk single-crystalline material.