Journal Article

FZJ-2020-03003

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Cation diffusion in polycrystalline thin films of monoclinic HfO 2 deposited by atomic layer deposition

Mueller, M. P. (Corresponding author) ; Pingen, K. ; Hardtdegen, A.FZJ* ; Aussen, S.FZJ* ; Kindsmueller, A. ; Hoffmann-Eifert, S.FZJ* ; De Souza, R. A.

2020
AIP Publ. Melville, NY

This record in other databases:  

Please use a persistent id in citations: http://hdl.handle.net/2128/25587  doi:10.1063/5.0013965

Abstract: Though present in small amounts and migrating at low rates, intrinsic cation defects play a central role in governing the operational lifetime of oxide-ion conducting materials through slow degradation processes such as interdiffusion, kinetic demixing, grain growth, and creep. In this study, a new experimental approach to characterizing the behavior of such slow-moving, minority defects is presented. Diffusion is probed in samples with a constant cation-defect concentration well above the equilibrium values. This approach is applied to monoclinic hafnium dioxide, m-HfO2. To this end, nanocrystalline thin films of m-HfO2 were prepared by atomic layer deposition. Diffusion experiments with ZrO2 as a diffusion source were performed in the temperature range 1173 ≤ T/K ≤ 1323 in air. The Zr diffusion profiles obtained subsequently by secondary ion mass spectrometry exhibited the following two features: the first feature was attributed to slow bulk diffusion and the second was attributed to combined fast grain-boundary diffusion and slow bulk diffusion. The activation enthalpy of Zr diffusion in bulk HfO2 was found to be (2.1 ± 0.2) eV. This result is consistent with the density-functional-theory calculations of hafnium-vacancy migration in m-HfO2, which yield values of ∼2 eV for a specific path. The activation enthalpy of the grain-boundary diffusion of (2.1 ± 0.3) eV is equal to that for bulk diffusion. This behavior is interpreted in terms of enhanced cation diffusion along space-charge layers

---

Contributing Institute(s):

1. Elektronische Materialien (PGI-7)
2. JARA Institut Green IT (PGI-10)
3. JARA-FIT (JARA-FIT)

Research Program(s):

1. 524 - Controlling Collective States (POF3-524) (POF3-524)

Appears in the scientific report 2020

---

Database coverage:
; ; ; ; Article Processing Charges ; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; DOAJ Seal ; Essential Science Indicators ; Fees ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

---