title: Doping change in the Bi-2212 superconductor directly induced by a hard X-ray nanobeam.
abstract: We describe the controlled use of a 17 keV X-ray synchrotron nanobeam to progressively change the oxygen doping level in Bi-2212 superconducting whisker-like single crystals. Our data combine structural and electrical information collected on the same crystals, showing a maximum change in the critical temperature Tc of 1.3 K and a maximum elongation of ∼1 Å in the c-axis length, compared to the as-grown conditions. Simulations of our experimental conditions by means of a finite element model exclude local heating induced by the X-ray nanobeam as a possible cause for the change in the doping level and suggest an important role of secondary electrons. These findings support the possible use of hard X-rays as a novel direct-writing, photoresist-free lithographic process for the fabrication of superconducting devices, with potential nanometric resolution and 3D capability.
authors.affiliation: Department of Physics, Interdepartmental Centre NIS, University of Torino , via Giuria 1, I-10125 Torino, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pagliero
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Mino
authors.forename: Elisa
authors.initials: E
authors.lastname: Borfecchia
authors.forename: Marco
authors.initials: M
authors.lastname: Truccato
authors.forename: Angelo
authors.initials: A
authors.lastname: Agostino
authors.forename: Lise
authors.initials: L
authors.lastname: Pascale
authors.forename: Emanuele
authors.initials: E
authors.lastname: Enrico
authors.forename: Natascia
authors.initials: N
authors.lastname: De Leo
authors.forename: Carlo
authors.initials: C
authors.lastname: Lamberti
authors.forename: Gema
authors.initials: G
authors.lastname: Martínez-Criado