Exploring Anisotropy and Domain Structures in YBCO Thin Films via Photoemission Electron Microscopy
ORAL
Abstract
The anisotropy in the electrical properties of YBa₂Cu₃O₇-δ (YBCO) plays a key role in understanding superconductivity in unconventional materials and optimizing the performance of YBCO-based Josephson junctions. In this study, we examine 40 nm-thick YBCO thin films irradiated with 300 keV helium ions using a Pelletron accelerator. Post-irradiation Photoemission Electron Microscopy (PEEM) revealed distinct contrasts between irradiated and non-irradiated regions, indicating a superconductor-to-insulator transition. In the non-irradiated regions, a two-domain pattern was observed, with a 25 meV variation in work function, likely linked to CuO- and BaO-rich surface areas. Similar domain structures were confirmed using high-resolution helium ion imaging. PEEM measurements also correlated with in-plane tunneling characteristics of YBCO, revealing an anisotropy factor of 1.5 between different in-plane axes. This study offers new insights into how material orientation affects Josephson junction performance and highlights the value of PEEM as a non-destructive tool for probing anisotropy in cuprate superconductors and its impact on superconducting properties and device behavior.
Acknowledgment: This work was supported by the Department of Energy NNSA grant DE-NA0004106 and AFOSR grant FA9550-23-1-0369.
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Publication: Investigation of the Anisotropy of Y-Ba-Cu-O Thin Films with Photoemission Electron Microscopy (submitted manuscript)
Presenters
Rochelle Y Qu
University of California, Riverside
Authors
Rochelle Y Qu
University of California, Riverside
Alexander M Boehm
Sandia National Laboratories
Jay LeFebvre
UCR, University of California, Riveside, University of California Riverside
Sreekar Vattipalli
University of California Riverside
Adhilsha Parachikunnumal
University of California, Riverside
Andrew R Kim
University of California, Davis, Sandia National Laboratories
