Journal Article

FZJ-2020-04262

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Ion distribution models for defect fluorite ZrO2 – AO1.5 (A = Ln, Y) solid solutions: I. Relationship between lattice parameter and composition

Bukaemskiy, A.FZJ* ; Vinograd, V. (Corresponding author)FZJ* ; Kowalski, P.FZJ*

2020
Elsevier Science Amsterdam [u.a.]

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Please use a persistent id in citations: http://hdl.handle.net/2128/26217  doi:10.1016/j.actamat.2020.10.045

Abstract: The composition dependence of the lattice constant, a, in AxB1-xO2-0.5xV0.5x, fluorite-type solid solutions (B = Zr, A = {Nd-Yb, Y}, V = oxygen vacancy) is characterized by changes in slope at x ~ 1/3, which cannot be described by existing models. Moreover, over the range of 0.15 ≤ x ≤ 1/3 the a vs. x data on all systems can be fitted with a linear equation, a = q + rx, with the same intercept, q, however, over the range of 1/3 ≤ x ≤ 1/2 the data bifurcate requiring different intercepts for A={Nd-Gd] and for A={Dy-Yb,Y} systems, implying steeper slopes for the first group. An adequate description is achieved via close-packing models involving two anion species, O2- and V, and three combinations of cation species, namely 8A, 7B, 8B (0 ≤ x ≤ 1/3), 7A, 8A, 7B (1/3 ≤ x ≤ 1/2) and 8A, 6B, 7B (1/3 ≤ x ≤ 1/2), that take into an account the constraint on the average coordination number, K(x), of K(x) = 8 – 2x and two additional short-range order (SRO) constrains referring to vacancy-vacancy avoidance and vacancy-to-Zr association. The consistent fit to a vs. x data with these models requires the effective size of the oxygen vacancy to be larger than the radius of the oxygen anion by ~11%. The latter observation seems to play an important role in the understanding of structure-property relationships in AxB1-xO2-0.5xV0.5x systems.

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Contributing Institute(s):

1. IEK-13 (IEK-13)
2. Nukleare Entsorgung und Reaktorsicherheit (IEK-6)

Research Program(s):

1. 113 - Methods and Concepts for Material Development (POF3-113) (POF3-113)
2. 161 - Nuclear Waste Management (POF3-161) (POF3-161)

Appears in the scientific report 2020

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

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