Dielectric Relaxation of La-Doped Zirconia Caused by Annealing Ambient
1 Department of Electrical and Electronic Engineering, Xi'an Jiaotong, Liverpool University, 215123, Suzhou, Jiangsu, China
2 Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
3 Department of Engineering, Materials Science and Engineering, University of Liverpool, Liverpool, L69 3GH, UK
4 Department of Chemistry, University of Liverpool, Liverpool, L69 3ZD, UK
Citation and License
Nanoscale Res Lett 2011, 6:48 doi:10.1007/s11671-010-9782-zPublished: 30 September 2010
La-doped zirconia films, deposited by ALD at 300°C, were found to be amorphous with dielectric constants (k-values) up to 19. A tetragonal or cubic phase was induced by post-deposition annealing (PDA) at 900°C in both nitrogen and air. Higher k-values (~32) were measured following PDA in air, but not after PDA in nitrogen. However, a significant dielectric relaxation was observed in the air-annealed film, and this is attributed to the formation of nano-crystallites. The relaxation behavior was modeled using the Curie–von Schweidler (CS) and Havriliak–Negami (HN) relationships. The k-value of the as-deposited films clearly shows a mixed CS and HN dependence on frequency. The CS dependence vanished after annealing in air, while the HN dependence disappeared after annealing in nitrogen.