High-Throughput Prediction of Thermodynamic Stabilities of Dopant-Defect Clusters at Misfit Dislocations in Perovskite Oxide Heterostructures

C Marzano and PP Dholabhai, JOURNAL OF PHYSICAL CHEMISTRY C, 127, 15988-15999 (2023).

DOI: 10.1021/acs.jpcc.3c02367

Complex oxide heterostructures and thin films have emergedas promisingcandidates for diverse applications, wherein interfaces formed byjoining two different oxides play a central role in novel propertiesthat are not present in the individual components. Lattice mismatchbetween the two oxides leads to the formation of misfit dislocations,which often influence vital material properties. In oxides, dopingis used as a strategy to improve properties, wherein inclusion ofaliovalent dopants leads to formation of oxygen vacancy defects. Atlow temperatures, these dopants and defects often form stable clusters.In semicoherent perovskite oxide heterostructures, the stability ofsuch clusters at misfit dislocations, while not well understood, isanticipated to impact interface-governed properties. Herein, we reportatomistic simulations elucidating the influence of misfit dislocationson the stability of dopant-defect clusters in SrTiO3/BaZrO3 heterostructures. SrO-BaO, SrO-ZrO2, BaO-TiO2, and ZrO2-TiO2 interfaces having dissimilar misfit dislocation structureswere considered. High- throughput computing was implemented to predictthe thermodynamic stabilities of 275,610 dopant-defect clusters inthe vicinity of misfit dislocations. The misfit dislocation structureof the given interface and corresponding atomic layer chemistry playa fundamental role in influencing the thermodynamic stability of geometricallydiverse clusters. A stark difference in cluster stability is observedat misfit dislocation lines and intersections as compared to the coherentterraces. These results offer an atomic scale perspective of the complexinterplay between dopants, point defects, and extended defects, whichis necessary to comprehend the functionalities of the perovskite oxideheterostructures.

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