DAMAGE IN Y-BA-CU-O FILMS PRODUCED BY HE-4 IONS

The question of destructibility of an ion beam technique applied to th e analysis of high temperature superconductors is discussed, namely th e influence of the often used analyzing He-4 ion beam on a monocrystal line YBa2Cu3O7 film. The rate of irradiation defect production is meas ured for 1 and 3.07 MeV He-4+ irradiation and compared with a Monte Ca rlo simulation. It is shown that the usual depth profiling by He-4 ion beams does not change the measured element profiles, but is destructi ve from the view point of the superconducting properties of a sample, due to the great number of defects produced. Using a large solid angle detector one can minimize the analyzing dose to avoid the destruction of superconducting properties.