Effect of high oxygen pressure annealing on superconducting Nd1.85Ce0.15CuO4 thin films by pulsed laser deposition from Cu-enriched targets

TL;DR

This study demonstrates that using copper-enriched targets in pulsed laser deposition improves the quality and superconducting properties of Nd1.85Ce0.15CuO4 thin films, especially under high oxygen pressure annealing, facilitating device integration.

Contribution

It introduces a non-stoichiometric target approach to enhance film quality and reduce dependence on annealing procedures in Nd-based cuprate superconductors.

Findings

Copper-enriched targets suppress parasitic phase formation.

Films maintain superconductivity after high-pressure oxygen annealing.

Enhanced film quality enables integration with hole-doped cuprates.

Abstract

We show that the quality of Nd1.85Ce0.15CuO4 films grown by pulsed laser deposition can be enhanced by using a non-stoichiometric target with extra copper added to suppress the formation of a parasitic (Nd, Ce)2O3 phase. The properties of these films are less dependent on the exact annealing procedure after deposition as compared to films grown from a stoichiometric target. Film growth can be followed by a 1 bar oxygen annealing, after an initial vacuum annealing, while retaining the superconducting properties and quality. This enables the integration of electron-doped cuprates with their hole-doped counterparts on a single chip, to create, for example, superconducting pn-junctions.