Effects of 1-MeV proton irradiation in Hg-based cuprate thin films

作者：A. A. Gapud, J.R. Liu, Judy Wu, W. N. Kang, Byeongwon Kang, Sang‐Ho Yun, W. K. Chu · 发表于：Physical review. B, Condensed matter · 年份：1997 · DOI：10.1103/physrevb.56.862 · 被引用次数：15 · 研究领域：Physics of Superconductivity and Magnetism、Superconductivity in MgB2 and Alloys、Superconducting Materials and Applications

We have studied the effects of 1-Mev proton irradiation on both superconducting properties and normal state resistivity of high-quality ${\mathrm{HgBa}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{6+\mathrm{\ensuremath{\delta}}}\mathrm{ }(\mathrm{H}\mathrm{g}\ensuremath{-}1212)$ and ${\mathrm{HgBa}}_{2}{\mathrm{Ca}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{8+\mathrm{\ensuremath{\delta}}}\mathrm{ }(\mathrm{H}\mathrm{g}\ensuremath{-}1223)$ thin films. At low proton doses, we observed a linear decrease of the superconducting transition temperature ${T}_{c}$ and a linear increase of the extrapolated residual resistivity as proton dose is increased. This is consistent with observations of other high-${T}_{c}$ superconductors while a lower dose threshold for suppressing the superconductivity is found in Hg-1212 and Hg-1223 films. To explain the linear dose dependence of ${T}_{c},$ we propose a model based on the proximity effect. An enhancement of up to 90% in the critical current density at low fields has also been observed in these films at low proton fluences that do not significantly degrade ${T}_{c}.$