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arXiv · 2605.10703

Freestanding GdBa2Cu3O7 Thin Films via Optimized Buffer Layer Design: Preserving Superconducting Properties

Kazumasa Iida·Kai Walter·Takafumi Hatano·Kose Morinaga·Manuela Erbe·Hongye Gao·Satoshi Hata·Jens Hänisch
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Abstract

Freestanding GdBa2Cu3O7 (GdBCO) superconducting thin films were fabricated using a water-soluble Sr3Al2O6 (SAO) sacrificial layer in combination with thermal release tape. An amorphous Al2O3 capping layer was introduced to suppress crack formation during the lift-off process. The influence of buffer-layer design inserted between the GdBCO and SAO layers was systematically investigated with respect to structural integrity and superconducting properties after lift-off. A LaAlO3/SrTiO3 bilayer buffer was found to be essential for maintaining epitaxial growth and a superconducting transition temperature (Tc) of approximately 92 K after lift-off, comparable to that of the as-grown films. In contrast, a reversed SrTiO3/LaAlO3 bilayer and single-layer buffer structures led to a suppression of Tc, highlighting the critical role of stacking sequence. These results demonstrate that optimization of the buffer-layer design is a key factor for realizing high-quality freestanding GdBCO films while maintaining their superconducting characteristics.

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Kazumasa Iida, Kai Walter, Takafumi Hatano, Kose Morinaga, Manuela Erbe, Hongye Gao, Satoshi Hata, Jens Hänisch. 2026-05-11. Freestanding GdBa2Cu3O7 Thin Films via Optimized Buffer Layer Design: Preserving Superconducting Properties. https://doi.org/10.1021/acsaelm.6c00542

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