Growth and characterization of nasicon thin films by the laser ablation method

Abstract

Thin films of nasicon structure have been grown from NaM 2(PO 4) 3 (M = Ti and Zr) targets onto silicon substrates by the laser ablation method. By the complementary use of electron microscopy, Rutherford backscattering spectrometry and X-ray diffraction techniques, the surface morphology of the deposited films, their composition and their crystalline structure have been studied as a function of the main growth conditions. Titanium-based composition yields smooth films that can only be crystallized by post-deposition high temperature annealing in oxygen or air. Zirconium-based films are directly crystallized during the deposition process, but exhibit a rough morphology associated to an important ‘splashing effect’ during the laser irradiation of the Zr-based target. Mixtures of Ti and Zr in the target lead to smooth in situ partly crystallized films.