Revealing the Deposition Mechanism of the Powder Aerosol Deposition Method Using Ceramic Oxide Core–Shell Particles

Abstract

The Powder Aerosol Deposition method (PAD) is a process to manufacture ceramic films completely at room temperature. Since the first reports by Akedo in the late 1990s, much research has been conducted to reveal the exact mechanism of the deposition process. However, it is still not fully understood. We tackled this challenge using core shell particles. Two coated oxides, Al2O3 core with a SiO2 shell and LiNi0.6Mn0.2Co0.2O2 core with a LiNbO3 shell, were investigated. Initially, the element ratios Al:Si and Ni:Nb of the powder were determined by EDX. In a second step, the change in the element ratios of Al:Si and Ni:Nb after deposition were investigated. The element ratios from powder to film strongly shift towards the shell‐elements, indicating that the particles fracture and only the outer parts of the particles are deposited. In the last step, we investigated cross‐sections of the deposited films with STEM combined with EDX and an EsB detector to unveil the element distribution within the film itself. Therefore, the following overall picture emerges: particles impact on the substrate or on previously deposited particle, fracture, and only a small part of the impacting particles that originate from the outer part of the impacting particle gets deposited.This article is protected by copyright. All rights reserved