EFFECTS OF 1-MEV PROTON IRRADIATION IN HG-BASED CUPRATE THIN-FILMS

We have studied the effects of 1-Mev proton irradiation on both superc onducting properties and normal state resistivity of high-quality HgBa 2CaCu2O6+delta (Hg-1212) and HgBa2Ca2Cu3O8+delta (Hg-1223) thin films. At low proton doses, we observed a linear decrease of the superconduc ting transition temperature T-c and a linear increase of the extrapola ted residual resistivity as proton dose is increased. This is consiste nt with observations of other high-T-c superconductors while a lower d ose threshold for suppressing the superconductivity is found in Hg-121 2 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 obser ved in these films at low proton fluences that do not significantly de grade T-c.