Volume 30, Issue 42 e202401581
Research Article

High-Pressure Synthesis and Recovery of Single Crystals of the Metastable Manganese Carbide, MnCx

Paul V. Marshall

Paul V. Marshall

Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003 United States

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Scott D. Thiel

Scott D. Thiel

Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003 United States

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Elizabeth E. Cote

Elizabeth E. Cote

Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003 United States

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John Arigbede

John Arigbede

Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003 United States

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Dr. Matthew L. Whitaker

Dr. Matthew L. Whitaker

Department of Geosciences, Stony Brook University, Stony Brook, NY, 11794-2100 United States

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Prof. James P. S. Walsh

Corresponding Author

Prof. James P. S. Walsh

Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003 United States

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First published: 21 May 2024

Graphical Abstract

Transition metal carbides are used widely throughout industry for their high hardness, superior resistance to corrosion, and stability under extremes of temperature and radiation. Here we describe the discovery of a novel sub-stoichiometric anti-NiAs-type compound, MnCx (P63/mmc), synthesized at pressures between ~5–10 GPa and recovered fully to ambient conditions as single crystals.

Abstract

Transition metal carbides find widespread use throughout industry due to their high strength and resilience under extreme conditions. However, they remain largely limited to compounds formed from the early d-block elements, since the mid-to-late transition metals do not form thermodynamically stable carbides. We report here the high-pressure bulk synthesis of large single crystals of a novel metastable manganese carbide compound, MnCx (P63/mmc), which adopts the anti-NiAs-type structure with significant substoichiometry at the carbon sites. We demonstrate how synthesis pressure modulates the carbon loading, with ~40 % occupancy being achieved at 9.9 GPa.

Conflict of interests

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.