Evolution of superconducting and normal state properties of YBa2Cu3O7−y thick films under 200 MeV Ag ion irradiation

► 200 MeV Ag ion irradiation was done on superconducting YBa2Cu3O7−y thick films. ► The fluence was varied from 1 × 1011 ions cm−2 to 5 × 1012 ions cm−2 in four steps. ► For 1 × 1011 ions cm−2, an increase in Tc and decrease of resistivity were observed. ► The increase of Tc is due to the oxygen ordering in CuO chain of YBa2Cu3O7−y films. ► The ordering is performed by ion induced secondary electrons at room temperature.