TY  - JOUR
AU  - Vinograd, Victor L.
AU  - Bukaemskiy, Andrey A.
TI  - Ion distribution models for defect fluorite ZrO2 - AO1.5 (A = Ln, Y) solid solutions: II. Thermodynamics of mixing and ordering
JO  - Acta materialia
VL  - 202
SN  - 1359-6454
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2021-05697
SP  - 55 - 67
PY  - 2021
AB  - Thermodynamic mixing properties of AxB1-xO2-0.5xV0.5x, fluorite-type solid solutions (B = Zr, A = {Nd-Yb, Y}, V = oxygen vacancy) are modelled as functions of four parameters, ΔH1, ΔH2, ΔH3 and ΔH4, which correspond to the enthalpy effects of the reactions 6A + 8B = 7A + 7B (1), 6A + 8B = 8A + 6B (2), 6B + 8B = 7B + 7B (3) and 6A + 8A = 7A + 7A (4), involving six cation species, 6A, 7A, 8A, 6B, 7B and 8B. The model predicts that the disordered configuration containing all cation species evolves with the decreasing temperature such that 6-fold coordinated cations tend to vanish within 0 ≤ x ≤ 1/2 domain, while 8-fold coordinated cations become extinct within 1/2 ≤ x ≤ 1 domain. The further evolution within the intervals of 0 ≤ x ≤ 1/3, 1/3 ≤ x ≤ 1/2, 1/2 ≤ x ≤ 2/3 and 2/3 ≤ x ≤ 1 favours the extinction of 7A, 8B, 7B and 6A cation species, respectively. With the further decrease in the temperature 6-fold B and 8-fold A cations reappear within the domains of 1/3 ≤ x ≤ 1/2 and 1/2 ≤ x ≤ 2/3 via the reaction 7A + 7B = 8A + 6B. The configurational entropy reduces along with these transformations. The model fits structural and calorimetric data on Zr-based AxB1-xO2-0.5xV0.5x systems and provides hints to understanding of ionic conductivity and radiation susceptibility data.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000599842800005
DO  - DOI:10.1016/j.actamat.2020.10.046
UR  - https://juser.fz-juelich.de/record/904127
ER  -