Speaker
Description
The use of nitride semiconductors such as AlN, GaN and InN for (opto)electronic applications has become paramount in recent years. High-pressure-derived nitrides with direct band gap, e.g. γ-Ge3N4 with spinel-type structure, are currently being explored. Similarly to alredy known ambient- and high pressure forms of the lighter group-4 nitride, Si3N4 and its solid solutions with Al and O, e.g. Si3-xAlxOxN4-x, γ-Ge3N4 could be modified by exchanging [Ge-N]+ pairs with [Ga-O]+ or even [Cr-O]+ pairs to create novel solid solutions with spinel-type structure. Other oxynitrides containing Ga and/or Ge are already known to show promising photocatalytic properties for water-splitting. Moreover, the introduction of a magnetic ion into the spinel structure could result in novel materials with frustrated magnetism.
In this contribution, we present results on the synthesis and first characterization of spinel compounds in the quintary element system Ge-Ga-Cr-O-N and its ternary and quarternerary subsystems.