Radiation effects in high-temperature YBa2Cu3O7-x superconducting thin films with low-energy protons for space radiation environments

Abstract

This paper presents the irradiation effects and microstructure evolution in YBa2Cu3O7-x (YBCO) thin films irradiated with low-energy protons. The microstructure changes can arise from atomic displacements characterized by micro-Raman spectroscopy. Providing different fluence low-proton irradiation conditions to simulate the space proton environment, the obvious properties change of the transition temperature Tc and critical current density Jc can be observed. In accordance with micro-Raman spectroscopy observations, the main components of proton-radiation-induced defects are that displacements of oxygen atoms in Cu–O chains. These oxygen defects acting as effective pinning centers for flux vortices increase the pinning force Fp and the critical current density Jc. However, a further healing process of broken Cu–O chains occurs with further proton irradiation, which leads to a weaker pinning force Fp and a decreased critical current density Jc. This work provides the damage profiles of the proton radiation on high-temperature YBCO superconducting thin films, which are extraordinarily important for the future superconductor applications in long-time space missions.