Proton irradiation effects on metal-YBCO interfaces

Highlights: • Memory devices should be optimized for their use in outer space or nuclear reactors. • YBCO Memristors withstand 10 MeV protons irradiation up to a fluence of 80 Gp/cm². • Irradiation effects are analyzed by the current-voltage characteristics of the device. • An equivalent circuit of the device and a microscopic model are proposed. • Results and simulations suggest that protons mainly displace oxygen ions from YBCO. 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 ~ 80⋅10⁹ p/cm² no changes in the electrical behavior of the device were observed, while for a fluence of ~ 300⋅10⁹ p/cm² it becomes less conducting. A detailed analysis of the room temperature IV characteristics based on the γ power exponent parameter [γ = 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.