Structural changes in YBa2Cu3O7 films irradiated with focused He+ ion beam

We will study the changes in the crystal lattice of YBa2Cu3O7 caused by focused He+ ion beam, which is a common tool for nanopatterning. In the case of the macroscopic irradiated areas, the YBa2Cu3O7 undergoes a superconductor-to-insulator transition which is accompanied by the change of the crystal lattice from orthorhombic to tetragonal. However we expect that the structural phase transition might be suppressed in the case of the small (micrometer-size) irradiated area due to impossibility of the crystal lattice to accommodate strong lattice distortions.
Using a focused He+ ion beam, we will irradiate small areas of a YBa2Cu3O7 film with different ion fluences. We will scan the irradiated areas with a nanofocused X-ray beam and measure (007) and (109)/(019) Bragg peaks to retrieve the lattice parameters in the irradiated areas. This spatially-resolved information will allow us to identify the structural changes and study the influence of ion fluence and size of the irradiated area.