Rapid, energy-efficient and pseudomorphic microwave-induced-metal-plasma (MIMP) synthesis of Mg2Si and Mg2Ge

Fan, Z., Ho, H.-N., Szczesny, R., Liu, W.-R. and Gregory, D. H. (2022) Rapid, energy-efficient and pseudomorphic microwave-induced-metal-plasma (MIMP) synthesis of Mg2Si and Mg2Ge. CrystEngComm, 24(32), pp. 5801-5809. (doi: 10.1039/D2CE00721E)

Abstract

Polycrystalline magnesium silicide, Mg2Si and magnesium germanide, Mg2Ge were synthesised from the elemental powders via the microwave-induced-metal-plasma (MIMP) approach at 200 W within 1 min in vacuo for the first time. The formation of reactive Mg plasma facilitated by the high-frequency electromagnetic field (2.45 GHz) is at the origin of the ultrafast reaction kinetics in these preparations. Powder X-ray diffraction (PXD), Scanning Electron Microscopy (SEM) combined with Energy Dispersive X-ray Spectroscopy (EDX) and X-ray Photoelectron Spectroscopy (XPS) attest to the high purity of the products. Both SEM and Transmission Electron Microscopy (with Selected Area Electron Diffraction) (TEM/SAED) demonstrate the pseudomophic nature of the metal plasma reactions such that use of nanoporous Ge starting material leads to the production of nanoporous germanide, Mg2Ge. Covalent Mg-Si and Mg-Ge bonds with partial ionic character are suggested by XPS, while the refined crystal structures are consistent with Mg-Mg interactions within the cubane-like clusters in Mg2X antifluorite unit cells. The MIMP method unlocks not only the sustainable synthesis of Mg2X materials but also the wider production of intermetallics and Zintl phases of prescribed morphology.

• Item Type: Articles
• Additional Information: W-R.L gratefully acknowledges the Ministry of Science and Technology, Taiwan, for support under project grants MOST 110-2923-E-006 -011, 110-3116-F-011-002, 110-2622-E-033-009, 109-2911-I-033-502 and 108-E-033-MY3.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Fan, Zhen and Gregory, Professor Duncan
• Authors: Fan, Z., Ho, H.-N., Szczesny, R., Liu, W.-R., and Gregory, D. H.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: CrystEngComm
• Publisher: Royal Society of Chemistry
• ISSN: 1466-8033
• ISSN (Online): 1466-8033
• Published Online: 25 July 2022
• Copyright Holders: Copyright © 2022 The Royal Society of Chemistry
• First Published: First published in CrystEngComm 24(32): 5801-5809
• Publisher Policy: Reproduced under a Creative Commons Licence

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
190912		High throughput microwave synthesis of Li-ion battery materials	Serena Corr	Engineering and Physical Sciences Research Council (EPSRC)	EP/N001982/1	Chemistry
305672		New non-oxide electrolytes for all-solid-state Li-ion batteries	Duncan Gregory	The Royal Society (ROYSOC)	IEC\R3\183040	Chemistry