Sputtering of high Tc superconductor YBa2Cu3O7-δ by high energy heavy ions

To investigate the electronic excitation effect on ion-induced atomic displacement, we have applied a carbon (C)-film collector method to measure the sputtering yields of YBa2Cu3O7-delta (YBCO) by high energy heavy ions. The collection efficiency of the C-films is calibrated by using 120 keV Ne+ ions and the values are obtained as 0.048, 0.076, 0.061 and 0.3 for Y, Ba, Cu and O, respectively. The total sputtering yields of YBCO induced by 198 MeV 1, 69 MeV Ni and 80 MeV S ions are evaluated as 1030, 580 and 100, respectively, including oxygen contribution. These values are larger by a factor of similar to 1000 than the calculated sputtering yield due to the elastic collision cascade, indicating a significant contribution of the electronic excitation to the sputtering yields. It also appeals that the total sputtering yields scale reasonably with the square of the electronic stopping power. (C) 2001 Elsevier Science B.V. All rights reserved.