Table 1. Mode assignment23, Raman mode frequencies, pressure coefficients, and the mode Gruneisen parameters γ of the Raman features of Sb2S3 calculated at a reference pressure P R.
| Modesymmetry | PR(GPa) | ωR(cm−1) | ∂ω/∂P(cm−1/GPa) | ∂2ω/∂P2(cm−1/GPa2) | γ |
|---|---|---|---|---|---|
| Ag(1) | 10−4 | 100.4 | 0.6 | −0.03 | 0.16 |
| B1g(1) | 10−4 | 108 | 2.2 | −0.06 | 0.55 |
| B1g(2) | 10−4 | 127.5 | 3.5 | −0.09 | 0.75 |
| Ag(2) | 10−4 | 153.8 | 9.7 | −0.4 | 1.72 |
| Ag(3) | 10−4 | 190.8 | 3.6 | −0.11 | 0.51 |
| B1g(3) | 10−4 | 202 | 2.6 | – | 0.35 |
| B1g(4) | 10−4 | 238 | 3.7 | −0.07 | 0.42 |
| Ag(4) | 10−4 | 281.5 | −0.9 | – | −0.09 |
| 5 | 271 | 3.1 | – | 0.74 | |
| B1g(5) | 10 − 4 | 300.1 | −1.1 | – | −0.1 |
| 5 | 295 | −0.6 | – | −0.13 | |
| Ag(5) | 307 | −0.8 | – | 0.07 | |
| M1 | 15 | 127 | 1 | – | – |
| M2 | 15 | 361 | 3.6 | – | – |
The pressure depencence of the Raman-active modes is described by the relation: ω(P) = ωR + αP + bP2. Mode Gruneisen parameters γ are determined from the relation: γ = (B0/ωR) × (∂ω/∂P); the bulk modulus B0 = 27.2 GPa (or B = 65 GPa at 5 GPa) was employed.