Opposite correlations between cation disordering and amorphization resistance in spinels versus pyrochlores

Understanding and predicting radiation damage evolution in complex materials is crucial for developing next-generation nuclear energy sources. Here, using a combination of ion beam irradiation, transmission electron microscopy and X-ray diffraction, we show that, contrary to the behaviour observed in pyrochlores, the amorphization resistance of spinel compounds correlates directly with the energy to disorder the structure. Using a combination of atomistic simulation techniques, we ascribe this behaviour to structural defects on the cation sublattice that are present in spinel but not in pyrochlore. Specifically, because of these structural defects, there are kinetic pathways for the relaxation of disorder in spinel that are absent in pyrochlore. This leads to a direct correlation between amorphization resistance and disordering energetics in spinel, the opposite of that observed in pyrochlores. These results provide new insight into the origins of amorphization resistance in complex oxides beyond fluorite derivatives

Estimation histories of the system parameters.

(a) Estimates for θ1. (b) Estimates for θ2. (C) Estimates for θ3. (d) Estimates for θ4.</p

Servo system.

Servo system.</p

Estimation error curves.

Estimation error curves.</p

Schematic of sandwich system with proposed scheme.

Schematic of sandwich system with proposed scheme.</p

Parameter estimation for deadzone.

(a) Estimates for kL. (b) Estimates for dL. (c) Estimates for kR. (d) Estimates for dR.</p

S1 Data -

(ZIP)</p

Auxiliary model structure.

Auxiliary model structure.</p

Monte Carlo run.

(a) Monte Carlo run. (b) Boxplot.</p

Model output.

(a) Output contrast. (b) Output error.</p