Antimony nitride discovered by theoretical structure prediction, rapid thermal annealing, and in situ X-ray diffraction

Nitride materials have promising properties for optoelectronics, but synthesis is challenging because of their metastable character. Therefore, even some simple binary nitrides have not been reported, and their properties remain unknown. Here, we report a metastable Sb-N phase. Unconstrained first-principle crystal-structure predictions suggest that a semiconducting layered SbN phase could be synthesized under activated nitrogen conditions. Experimentally, we approach the synthesis by rapid thermal annealing of an amorphous thin-film precursor. In situ X-ray diffraction monitoring reveals a transient phase appearing at 500°C and lasting for 17 s. With molecular dynamics simulations, we conclude that the phase observed is related to the predicted ground-state structure but that it contains stacking variations. This research highlights the synergy between computational materials discovery and in situ structural characterization during synthesis and processing, enabling the identification and synthesizability of new materials at the frontier of thermodynamically metastable regions.