Table 1. Calculated Lattice Parameters (a and c), Internal Parameter (zM), c/a Ratio, and Formation Energy of Hf2AX [A = S, Se, Te; X = B, C] MAX Phase Compounds.
| phase | a (Å) | % of deviation | c (Å) | % of deviation | zM | c/a | EF (eV/atom) | references |
|---|---|---|---|---|---|---|---|---|
| Hf2SB | 3.506 | 1.13 | 12.229 | 1.03 | 0.603 | 3.487 | –1.26 | this study |
| 3.467 | 12.104 | 0.604 | 3.491 | expt.20 | ||||
| 3.482 | 0.43 | 12.137 | 0.27 | 0.603 | 3.485 | theo.20 | ||
| 3.506 | 1.13 | 12.159 | 0.45 | 0.603 | 3.468 | theo.14 | ||
| 3.508 | 1.20 | 12.222 | 0.97 | 0.603 | 3.483 | theo.26 | ||
| Hf2SC | 3.300 | 2.0 | 11.757 | 2.1 | 0.099 | 3.562 | –1.13 | this study |
| 3.369 | 12.017 | 0.600 | 3.566 | expt.20 | ||||
| 3.360 | 11.997 | 3.570 | expt.21 | |||||
| 3.424 | 1.63 | 12.184 | 1.39 | 0.600 | 3.558 | theo.14 | ||
| 3.369 | 0.01 | 11.993 | 0.19 | 0.101 | 3.560 | theo.22 | ||
| Hf2SeB | 3.552 | 0.85 | 12.559 | 0.099 | 3.535 | –1.16 | this study | |
| 3.522 | 12.478 | 0.598 | 3.542 | expt.26 | ||||
| 3.550 | 0.79 | 12.573 | 0.599 | 3.541 | theo.26 | |||
| Hf2SeC | 3.470 | 1.42 | 12.514 | 0.99 | 0.095 | 3.605 | –1.03 | this study |
| 3.422 | 12.391 | 3.621 | expt.24 | |||||
| 3.436 | 0.41 | 12.452 | 0.49 | 3.624 | theo.24 | |||
| 3.438 | 0.47 | 12.501 | 0.89 | 3.636 | theo.27 | |||
| Hf2TeB | 3.629 | 0.68 | 13.355 | 1.74 | 0.591 | 3.679 | –0.86 | this study |
| 3.604 | 13.126 | 3.641 | expt.35 | |||||
| Hf2TeC | 3.559 | 13.236 | 0.088 | 3.718 | –0.69 | this study |