Unveiling the Interfacial Reconstruction Mechanism Enabling Stable Growth of the Delafossite PdCoO2 on Al2O3 and LaAlO3

Scheid A, Heil T, Suyolcu YE, Song Q, Enderlein N, Nono Tchiomo AP, Ngabonziza P, Hansmann P, Schlom DG, van Aken PA (2025)

Publication Type: Journal article

Publication year: 2025

Journal

ACS Applied Materials and Interfaces American Chemical Society

DOI: 10.1021/acsami.5c03536

Abstract

Delafossites, composed of noble metal (A+) and strongly correlated sublayers (BO2-), form natural superlattices with highly anisotropic properties. These properties hold significant promise for various applications, but their exploitation hinges on the successful growth of high-quality thin films on suitable substrates. Unfortunately, the unique lattice geometry of delafossites presents a significant challenge to thin-film fabrication. Different delafossites grow differently, even when deposited on the same substrate, ranging from successful epitaxy to complete growth suppression. These variations often lack a clear correlation to obvious causes like lattice mismatch. Unidentified stabilization mechanisms appear to enable growth in certain cases, allowing these materials to form stable thin films or act as buffer layers for subsequent delafossite growth. This study employs advanced scanning transmission electron microscopy techniques to investigate the nucleation mechanism underlying the stable growth of PdCoO2 films on Al2O3 and LaAlO3 substrates grown via molecular-beam epitaxy. Our findings reveal the presence of a secondary phase within the substrate surface that stabilizes the films. This mechanism deviates from the conventional understanding of strain relief mechanisms at oxide heterostructure interfaces and differs significantly from those observed for Cu-based delafossites.

Authors with CRIS profile

Niklas Enderlein Professur für Theoretische Physik mit dem Schwerpunkt Molekulare Materialien Philipp Hansmann Professur für Theoretische Physik mit dem Schwerpunkt Molekulare Materialien

Involved external institutions

Max-Planck-Institut für Festkörperforschung DE Germany (DE) Cornell University US United States (USA) (US) Louisiana State University US United States (USA) (US)

How to cite

APA:

Scheid, A., Heil, T., Suyolcu, Y.E., Song, Q., Enderlein, N., Nono Tchiomo, A.P.,... van Aken, P.A. (2025). Unveiling the Interfacial Reconstruction Mechanism Enabling Stable Growth of the Delafossite PdCoO2 on Al2O3 and LaAlO3. ACS Applied Materials and Interfaces. https://doi.org/10.1021/acsami.5c03536

MLA:

Scheid, Anna, et al. "Unveiling the Interfacial Reconstruction Mechanism Enabling Stable Growth of the Delafossite PdCoO2 on Al2O3 and LaAlO3." ACS Applied Materials and Interfaces (2025).

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