Energetic Ion Irradiation-Induced Disordered Nanochannels for Fast Ion Conduction

Nanoscale core–shell structure and recrystallization of swift heavy ion tracks in SrTiO3

“…Meanwhile, nuclear energy loss remains negligible throughout this range except in the end-of-range regions, which is consistent with previous studies on various oxide systems. 6,10,25,34,35 These calculations provide a guideline to select the penetration depth for atomic-scale STEM investigations where the structural transformations are dominated by electronic energy-loss on incident ions in the lattice without nuclear interaction influence. It is assumed that ion-tracks would occur due to the local thermal spike during electronic energy-loss in low-conductive SrTiO 3 .…”

“…5,6 The local disorders at the atomic sites leading to the formation of new metastable phases, such as weberite and defect-fluorite, have also been revealed in several pyrochlore structure oxides with various combinations of A-site (Gd, Sm, Yb, Hf, Er) and B-site (Ti, Zr, Sn) cations. [6][7][8][9][10] Under the irradiation of 2.8 MeV Au ion, a percolation of the disordered crystalline phase at the interface of LaMnO 3 and SrTiO 3 is observed. 11 All these findings highlight the importance of a detailed understanding of atomic arrangement to determine the phase transformation mechanisms resulting from ion-irradiation events, which is the focus of the present work.…”

∑3 Twin Boundaries in Gd2Ti2O7 Pyrochlore: Pathways for Oxygen Migration

“…The green highlighted area represents the TB region where the migration barrier calculations are performed subsequently. Overall, the atomic relaxation is performed 25 over the atomic model to achieve a thermodynamically stable structure, representable for understanding the oxygen migration behavior.…”

“…From the perspective of oxygen conductivity, pyrochlore-structured oxides (A 2 B 2 O 7 ) are significantly interesting materials − and are the focus of the present study. Due to the intrinsic possession of one ordered oxygen vacancy site (8b) per eight oxygen sites in the unit cell, the pyrochlore structure facilitates the fast diffusion of oxygen atoms and thus presents a huge opportunity in oxygen transport . The application of A 2 B 2 O 7 oxides is broadened to their disordered defect-fluorite structure derivative, which is previously reported to have enhanced oxygen diffusivity due to a decrease in migration energy barrier caused by chemical randomness of A and B cations leading to unlocking of the oxygen vacancies in the unit cell. , Since the structural phase transformation from pyrochlore to defect-fluorite to achieve high oxygen diffusion is a challenge that requires extreme conditions, − the use of TB interfaces in pyrochlore oxides as pathways for oxygen transport is proposed as a novel alternative solution in this work.…”

Probing Multiscale Disorder in Pyrochlore and Related Complex Oxides in the Transmission Electron Microscope: A Review

“…STEM techniques have been used to explore the structure of various pyrochlore and fluorite systems ( Gallagher et al, 2016 ; Sachan et al, 2017b ; Sachan et al, 2018 ; Sachan et al, 2019 ; Spurgeon et al, 2019 ; Lee et al, 2020 ; Spurgeon, 2020 ). See reference ( MacLaren and Ramasse, 2014 ) for a review of STEM techniques applied to functional oxides beyond pyrochlore and fluorite systems.…”