Investigation of Structural and Optical Properties of GDC Thin Films Deposited by Reactive Magnetron Sputtering

Abstract

The purpose of this paper was to analyze structural and optical properties of gadolinia-doped ceria (GDC, Ce0.9Gd0.1O1.95) thin films. At first the ceria-gadolinia multilayer sandwich systems (4-12 layers) were deposited using reactive magnetron sputtering in the O2/Ar gas mixtures. The films were formed with ≈ 90% ceria and ≈ 10% gadolinia. The GDC thin films deposited on Si (111) substrate were annealed at 600• C for 1 h in air. The thickness of the formed GDC multilayer systems was about 600 nm. The GDC thin film microstructure was investigated by X-ray diffraction and scanning electron microscopy. The texture coefficient T c(hkl) of GDC films was evaluated from the X-ray diffraction patterns. The crystallite size of GDC films was estimated from the Scherrer equation. Optical properties of the annealed GDC thin films were examined using a laser ellipsometer. The results show that the number of layers has the influence on GDC thin film formation. As follows from the analysis of structural and optical properties of GDC 12 layer system annealed at 600• C for one hour in air has the highest refractive index n = 2.17.

Optimized magnetron sputtering process for the deposition of gadolinia doped ceria layers with controlled structural properties

“…In the works reported on the sputter deposition of GDC, only few papers report information about the crystalline orientation of the deposited films. Most of them indicate a random orientation [3,4,11,12,14,[17][18][19][20][21]29,46] and only a few report a preferential [111] orientation [10,13,26,30,34]. The change from random to [111] orientation for the films deposited at the shortest distance in our work is in agreement with these works.…”

“…Among these techniques, magnetron sputtering offers the advantage of easy scalability to industrial processes. There are several reports of the deposition of GDC films using both radio frequency (RF) [10][11][12][13][14][15][16][17][18][19] and direct current (DC) [4,7,[20][21][22][23][24][25][26][27][28][29][30][31][32] magnetron sputtering, as well as high power impulse magnetron sputtering (HiPIMS) [33,34]. The different methods have each their own advantages and drawbacks.…”

“…While many of the publications on sputtering of GDC focus on the properties of the deposited GDC films [10,11,[14][15][16][17][19][20][21][22]26,29,31,32], in this work, we want to focus on the process itself and on the optimization of the deposition conditions in order to achieve dense, stoichiometric GDC films at a high growth rate. In addition, we studied the influence of the process parameters such as the target-substrate distance, the oxygen flow rate and the substrate bias on the crystallographic orientation of the films.…”

Magnesium Oxide Thin Films with Tunable Crystallographic Preferred Orientation via Aerosol‐Assisted CVD

“…Furthermore, with the exception of the film from methanol at 400 °C, the films were found to be insoluble in acid (HNO 3 , 0.25 M) and base (KOH, 0.60 M). From texture coefficient calculations, all crystalline films showed a preferred orientation along the (200) plane. Furthermore, it was found that the (200) diffraction peak became more dominant with increasing temperature when films were deposited using methanol.…”

Growth and Correlation of the Physical and Structural Properties of Hexagonal Nanocrystalline Nickel Oxide Thin Films with Film Thickness

“…Therefore, under the present experimental condition of sputtered nickel oxide films, the crystallites preferred to grow on plane (101). The texture coefficient T c (hkl) examined the preferred growth/orientation according to the following equation [24,25]:…”