Enhancement and degradation of Tc in Bi-HTSC due to Li3+ irradiations

TLDR: In this article, the superconducting critical temperature of Li-irradiation of O-rich Bi(2.2.1.2) with excess oxygen and O-content less than the optimum was investigated.

Abstract: Radiation damage in Bi2Sr2CaCu2O8+δ or Bi(2 2 1 2) by 55 MeV Li3+-beam has been studied from electrical resistivity and X-ray diffraction characterizations. This irradiation increases electrical resistivity and broadens X-ray diffraction lines by generating defects in all samples. But superconducting critical temperature, Tc, is seen to increase for Bi(2 2 1 2) with excess oxygen and decrease for Bi(2 2 1 2) with O-content less than the optimum, that gives maximum Tc. This increase of the superconducting critical temperature on Li-irradiation of O-rich Bi(2 2 1 2) as well as the decrease for low-O Bi(2 2 1 2) is due to O-displacement. This is in agreement with our earlier He-irradiation results.