title: Dopant size effects on novel functionalities: High-temperature interfacial superconductivity.
abstract: Among the range of complex interactions, especially at the interfaces of epitaxial oxide systems, contributing to the occurrence of intriguing effects, a predominant role is played by the local structural parameters. In this study, oxide molecular beam epitaxy grown lanthanum cuprate-based bilayers (consisting of a metallic (M) and an insulating phase (I)), in which high-temperature superconductivity arises as a consequence of interface effects, are considered. With the aim of assessing the role of the dopant size on local crystal structure and chemistry, and on the interface functionalities, different dopants (Ca2+, Sr2+and, Ba2+) are employed in the M-phase, and the M-I bilayers are investigated by complementary techniques, including spherical-aberration-corrected scanning transmission electron microscopy. A series of exciting outcomes are found: (i) the average out-of-plane lattice parameter of the bilayers is linearly dependent on the dopant ion size, (ii) each dopant redistributes at the interface with a characteristic diffusion length, and (iii) the superconductivity properties are highly dependent on the dopant of choice. Hence, this study highlights the profound impact of the dopant size and related interface chemistry on the functionalities of superconducting oxide systems.
authors.affiliation: Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569, Stuttgart, Germany. y.e.suyolcu@fkf.mpg.de.
authors.forename: Y Eren
authors.initials: YE
authors.lastname: Suyolcu
authors.affiliation: Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569, Stuttgart, Germany.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569, Stuttgart, Germany.
authors.forename: Federico
authors.initials: F
authors.lastname: Baiutti
authors.affiliation: Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569, Stuttgart, Germany.|Al-Nahrain Nanorenewable Energy Research Center, Al-Nahrain University, Baghdad, Iraq.
authors.forename: Ameer
authors.initials: A
authors.lastname: Al-Temimy
authors.affiliation: Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569, Stuttgart, Germany.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Gregori
authors.affiliation: Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569, Stuttgart, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Cristiani
authors.affiliation: Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569, Stuttgart, Germany.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Sigle
authors.affiliation: Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569, Stuttgart, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Maier
authors.affiliation: Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569, Stuttgart, Germany.
authors.forename: Peter A
authors.initials: PA
authors.lastname: van Aken
authors.affiliation: Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569, Stuttgart, Germany.
authors.forename: Gennady
authors.initials: G
authors.lastname: Logvenov