Dielectric Relaxation of La-Doped Zirconia Caused by Annealing Ambient

C Z Zhao; M Werner; S Taylor; P R Chalker; A C Jones; Chun Zhao

doi:10.1007/s11671-010-9782-z

Dielectric Relaxation of La-Doped Zirconia Caused by Annealing Ambient

Nanoscale Res Lett. 2011 Dec;6(1):48. doi: 10.1007/s11671-010-9782-z. Epub 2010 Sep 30.

Authors

C Z Zhao^{1

2}, M Werner^{3

4}, S Taylor³, P R Chalker⁴, A C Jones⁵, Chun Zhao^{6

3}

Affiliations

¹ Department of Electrical and Electronic Engineering, Xi'an Jiaotong, Liverpool University, 215123, Suzhou, Jiangsu, China. [email protected].
² Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK. [email protected].
³ Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK.
⁴ Department of Engineering, Materials Science and Engineering, University of Liverpool, Liverpool, L69 3GH, UK.
⁵ Department of Chemistry, University of Liverpool, Liverpool, L69 3ZD, UK.
⁶ Department of Electrical and Electronic Engineering, Xi'an Jiaotong, Liverpool University, 215123, Suzhou, Jiangsu, China.

Abstract

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.

Keywords: La; La0.35Zr0.65O2; ZrO2.