TABLE II.
A summary of theoretical results for top five SnN candidate structures based on the XRD peak search-match algorithm, in comparison with the experimental observations for the SnN1−δ sample and theoretical calculations for Sn3N4. The corresponding lattice parameters are provided in Table S3.53 The most likely structure of the SnN1−δ samples is the distorted SG2 SnN structure related to the delafossite SnN (SG166) that is 96 meV/at. higher in energy than the lowest energy SG12 structure.
| Sn3N4 | SG12 | SG62 | SG6 | SG25 | SG166 | SG2 | Expt. SnN1−δ | |
|---|---|---|---|---|---|---|---|---|
| HF, meV | 0 | 0 | 5 | 6 | 55 | 96 | 90 | >Sn3N4 + Sn |
| XRD | No | No | No | No | Maybe | Maybe | Maybe | Broad peaks |
| Raman | No | Maybe | No | Maybe | No | No | Yes | Two doublets |
| XAS | Yes | Maybe | Maybe | Yes | Maybe | Yes | Yes | Two peaks |
| SAED | No | Yes | Maybe | Yes | Maybe | Maybe | Yes | Small u.c. |
| XPS | No | Yes | Yes | Yes | Yes | No | Yes | Two N peaks |
| Electrical | Semicond. | Semicond. | Semicond. | Semimet. | Metal | Semimet. | Semimet. | Degenerate |
| Eg, eV | 1.8 | 0.9 | 0.9 | 0.8 | 0.0 | 1.4 | 1.4 | 1.0-2.0 |
| Similarity | 1.00 | 0.43 | 0.49 | 0.57 | 0.53 | 0.75 | 0.78 | Likely |