Hokkaido University Research Profiles

Nanotechnology / Materials

Low-temperature Nitridation Method Using Sodium Amide

Nitride and oxynitride synthesis without using ammonia gas cylinder

This is a method used to convert oxides and other materials into nitrides and oxynitrides at low temperatures (300°C or less) by using a sodium amide melt to trigger a reaction with a highly concentrated and active nitrogen source. Nitrides and oxynitrides can be synthesized without having to prepare toxic ammonia gas cylinders.

Content of research

This is a new method for nitridation of oxides at low temperatures (300℃ or less). Conventional nitridation methods require the installation of toxic ammonia gas cylinders and toxic ammonia gas recovery facilities, and also use a large amount of ammonia due to the low ammonia gas usage rate. With the present method, the use of sodium amide as a flux minimizes the use of toxic ammonia and makes it possible to obtain oxynitride and nitride nanocrystals at low temperatures. Since sodium amide is a solid nitrogen source, it eliminates the need to install ammonia liquid cylinders. We have also discovered a method to synthesize oxynitrides by mixing chloride and sodium amide through an instantaneous temperature-programmed reaction.

Potential for social implementation

  • ・Synthesis of oxynitride and nitride nanopowders
  • ・Functional materials such as photocatalysts, electrochemical catalysts, magnetic materials, and radio wave absorbers
  • ・Surface nitriding treatment of oxides

Appealing points to industry and local governments

In general, nitride and oxynitride synthesis requires capital investment in and preparation of ammonia gas cylinders, and exhaust and other equipment. With this method, research on nitride and oxynitride can be started without using ammonia gas cylinders.