Effects of Kr and Xe ion irradiation on the structure of Y₂O₃ nanoprecipitates in YBCO thin film conductors

ABSTRACT

The response of Y₂O₃ nanoprecipitates in a 1-µm YBa₂Cu₃O_7-x layer from a superconducting wire Ag/YBCO/buffer metal oxides/Hastelloy to 107 MeV Kr and 167 MeV Xe ion irradiation was investigated using a combination of transmission electron microscopy, diffraction and X-ray energy-dispersive spectrometry. The direct observation of the radiation-induced tracks in Y₂O₃ nanocrystals is reported for the first time to the authors’ best knowledge. Structureless damaged regions of 5–9 nm (average 8 nm) in diameter were observed in Y₂O₃ nanocrystals when the electronic stopping power S_e was about or higher than 4.7 keV/nm. This value of S_e is the upper estimate of the minimum electronic stopping power to create damage in yttria nanocrystals. The electron diffraction patterns, high-resolution transmission electron microscopy, high-resolution scanning transmission electron microscopy, Fourier transform patterns from areas extending a few nanometres around the tracks show that yttria and YBCO keep their respective cubic and orthorhombic pristine structures.

KEYWORDS:

• Yttria
• YBCO
• Kr and Xe ions
• radiation damage
• transmission electron microscopy
• electron diffraction

Acknowledgements

The authors greatly appreciate the discussion of the results with Professor A.E. Volkov (Lebedev Physical Institute of the Russian Academy of Sciences, Russia). We thank Dr. N.B. Bolotina for English editing this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.