Effects of high-energy, heavy ion irradiation on the properties of Y-Ba-Cu-O high-Tc
superconductors are examined. The irradiating medium consists of accelerated Bi-ions, having
atomic weight of 114.82. The detected hysteresis loops have very different forms and sizes in
unirradiated and in irradiated states, referring to the strong effect of the irradiation. Striking
variations of critical current- and magnetic parameters up to the extent of 30-40% in this series of
specimens were detected. Their direct reason can be looked for in the change of the atomicmolecular
microstructure of the specimens, as an effect due to the irradiation. This is decided by
both of the energy and density of the ions arriving onto the surface of the samples [1,2]. It means
that the effect produced by the irradiating individual ions depends also on the exact local place of
the specimens, on nanometer scale, determined by their given molecular structure, bonding
relationships and microstructural stability. In this way, the irradiation experiments can provide
some new information on the atomic-molecular properties of the specimens in question. As a
genuine smart material, the Y1Ba2Cu3O7-d high-Tc superconductor is able to reply to any external
influence, changing its own qualities according to that effect.