Table 3 Micro-Raman spectra of the tested areas (cm−1)
5-1 blue | 5-3 light blue | 18-1 blue | 30-1 blue | 40 blue | Phase or functional group | 25 purple | 28 purple | 40 purple | Phase or functional group |
|---|---|---|---|---|---|---|---|---|---|
1095 | – | – | 1095 | 1086 | HB | 983 | 985 | 986 | HP/BaSO4 |
– | 981 | 985 | 987 | – | HB | 751 | – | – | Si3O96− |
– | – | – | 787 | – | HB | 578 | 588 | 581 | HP/δ(SiO2) |
– | 584 | 587 | 555 | – | HB | 504 | 516 | 505 | HP/Si4O128− |
– | 508 | 516 | – | – | Si4O12 | 446 | 466 | 449 | HP/SiO2 |
– | 448 | 464 | – | – | SiO2 | – | 382 | 374 | HP/(CuO) |
423 | – | – | 423 | 423 | SiO32−(glass)/HB | 357 | 356 | – | HP |
379 | 370 | – | 379 | 379 | HB | – | 274 | – | HP/(CuO) |
– | 346 | 355 | – | – | HP | 266 | – | 269 | β-BaSi2O5 |
– | 269 | 275 | – | 273 | β-BaSi2O5 | – | 240 | – | HP |