| Data of high intensity peak of XRD at different temperatures | Θ (degree) | Β (radian) (×10−3) | Particle size (nm) |
| PBT-30˚C | 14.646 | 7.10 | 19.55 |
| PBT-500˚C | 15.741 | 6.94 | 20.00 |
| PBT-850˚C | 15.808 | 6.04 | 22.97 |
| PBT-900˚C | 24.409 | 5.34 | 25.99 |