Mapping of Structural Changes Induced by X-ray Nanopatterning via Nano-X-ray Diffraction and Corresponding Electrical Effects

We have investigated the modifications induced in high-Tc superconductor Bi2Sr2CaCu2O8+δ (Bi-2212) single crystals by irradiation with an X-ray nanobeam 250 × 250 nm2 in size with E = 14.85 keV and a time-averaged photon flux φ0 = 7.53 × 108 ph s-1. Crystals were mounted onto amorphous substrates with electrical contacts to allow for both X-ray diffraction (XRD) and electrical measurements on the same sample. Changes in the domain structure were monitored via space-resolved nano-XRD mapping, whereas electrical properties were measured off-line at different levels of irradiation dose. The results show that irradiation induces both an increase of the mosaicity spread and a localized release of the mechanical stress of the crystals. This implies a transient local change of mechanical properties that could be due to thermal fatigue or nonthermal melting. Analysis of the electrical properties of the irradiated regions indicates a strong underdoping effect by the nanobeam and an exponential increase of the normal-state resistivity with the irradiation dose, according to the average rate α = (1.48 ± 0.12) × 10-11 Gy-1. These results represent an important step toward the full development of the X-ray nanopatterning technique.