Near-surface modification of defective KTaO₃ by ionizing ion irradiation

Journal Article · 14 June 2021 · Journal of Physics. D, Applied Physics

DOI: https://doi.org/10.1088/1361-6463/ac0b11 · OSTI ID:1820798

Velisa, Gihan  ^[1]; Zarkadoula, Eva  ^[2]; Iancu, Decebal ^[3]; Mihai, Maria Diana ^[4]; Grygiel, Clara ^[5]; Monnet, Isabelle ^[5]; Kombaiah, Boopathy  ^[4]; Zhang, Yanwen  ^[6]; Weber, William J.  ^[7]

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1. Horia Hulubei National Institute for Physics and Nuclear Engineering, Magurele (Romania); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Extreme Light Infrastructure, Nuclear Physics (ELI–NP), Magurele (Romania)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division
3. Horia Hulubei National Institute for Physics and Nuclear Engineering, Magurele (Romania); Univ. of Bucharest, Magurele (Romania). Faculty of Physics
4. Horia Hulubei National Institute for Physics and Nuclear Engineering, Magurele (Romania)
5. Normandie Univ. Caen (France). Centre de Recherche sur les Ions, les Matériaux et la Photonique, CEA, CNRS, ENSICAEN, UNICAEN
6. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering
7. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division

The synergistic effect of nuclear (S_n) and electronic (S_e) energy loss observed in some ABO₃ perovskites has attracted considerable attention due to the real possibility to modify various near-surface properties, such as the electronic and optical properties, by patterning ion tracks in the defective near-surface regions. In this study, we show that low-energy ion-induced disordering in conjunction with ionizing ion irradiation (18 MeV Si, 21 MeV Ni and 91.6 MeV Xe) is a promising approach for tailoring ion tracks in the near-surface of defective KTaO₃. Experimental characterization and computer simulations reveal that the size of these latent ion tracks increases with S_e and level of pre-existing damage. These results further reveal that the threshold S_e value (S_e^th) for track creation increases with decreasing pre-damage level. The values of S_e^th increase from 5.02 keV nm^-1, for a pre-existing fractional disorder of 0.53 in KTaO₃, to 10.81 keV nm^-1 for pristine KTaO₃. Above these thresholds, amorphous latent tracks are produced due local melting and rapid quenching. Below a disorder fraction of 0.08 and S_e ≤ 6.68 keV nm^-1, the synergistic effect is not active, and damage accumulation is suppressed due to a competing ionization-induced damage annealing process. These results indicate that, depending on S_e and the amount of pre-existing damage, highly ionizing ions can either enhance or suppress damage accumulation in KTaO₃, thus providing a pathway to tailoring defects states. Comprehending the conflicting roles of highly ionizing ions in defective ABO₃ oxides is vital for understanding and predictive modeling of ion-solid interactions in complex oxides, as well as for achieving control over ion track size in the near-surface of defective KTaO₃.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1820798
• Journal Information: Journal of Physics. D, Applied Physics, Vol. 54, Issue 37; ISSN 0022-3727
• Publisher: IOP PublishingCopyright Statement
• Country of Publication: United States
• Language: English