Proton irradiation effects on metal-YBCO interfaces

TL;DR

This study investigates how 10 MeV proton irradiation affects YBCO-based devices, revealing that high fluences cause reduced conductivity likely due to oxygen atom displacement within the lattice.

Contribution

It provides detailed analysis of proton irradiation effects on YBCO interfaces, including conduction mechanism insights and an equivalent circuit model, supported by Monte Carlo simulations.

Findings

No electrical changes up to 80×10^9 p/cm^2 fluence

Reduced conductivity at 300×10^9 p/cm^2 fluence

Oxygen atom displacement within YBCO lattice

Abstract

10 MeV proton-irradiation effects on a YBCO-based test structure were analyzed by measuring its current-voltage (IV) characteristics for different cumulated fluences. For fluences of up to $\sim$80$\cdot$10$^9$~p/cm$^2$ no changes in the electrical behavior of the device were observed, while for a fluence of $\sim$~300$\cdot$10$^9~$ p/cm$^2$ it becomes less conducting. A detailed analysis of the room temperature IV characteristics based on the $\gamma$ power exponent parameter [$\gamma=dLn(I)/dLn(V)$] allowed us to reveal the main conduction mechanisms as well as to establish the equivalent circuit model of the device. The changes produced in the electrical behavior, in accordance with Monte Carlo TRIM simulations, suggest that the main effect induced by protons is the displacement of oxygen atoms within the YBCO lattice, particularly from oxygen-rich to oxygen-poor areas, where they become trapped.