Metal nitride and alloy synthesis using high pressures and temperatures

Abstract

In a laser-heated diamond cell, we prepare high-density metal nitrides by reaction of an element with a nitrogen pressure medium, and binary alloys by reaction of one element with another in preferably an inert pressure medium such as argon or neon. One of our objectives is to establish the parameters required for the synthesis of both metal nitrides and alloys in a multianvil press using elemental starting materials. We have already synthesized transition metal nitrides in a multianvil press using elemental starting materials, including hexagonal nickel nitride and alkali rhenium nitrides. Here, starting with the elements, we report the synthesis of magnesium sodium iron nitride and magnesium iron nitride at pressures and temperatures up to 15 GPa and 1800 K, respectively, and recovery of a GeSi alloy from 15 GPa after heating the elements at 1500 K. We also briefly present focused ion beam processing of recovered reaction products tailored for electron microscopy analysis.

Keywords:

• solid–solid transitions
• high pressure
• synthesis
• electron microscopy
• alloys
• ceramics

Acknowledgements

High-pressure experiments were performed at the Bayerisches Geoinstitut under the EU ‘Research Infrastructures: Transnational Access’ Programme (Contract No. 505320 (RITA) – High Pressure). We thank Gudmundur Guddfinnsson for his assistance. We further thank C. Guillaume and N. Odling. We also thank M. Hall for demanding solids processing and J. Craven and Emma Passmore for assistance with scanning microscopy. We also acknowledge the use of the EPSRC Chemical Database Service at Daresbury. We also thank the University of Edinburgh Development Trust for their support.