|                               | Sample | Sample        | Sample        | Sample         | Sample        |
|                               | PG     | GCA           | GCB           | GCC            | GCD           |
| Heat treatment                | 0      | 5h at 360degC | 5h at 400degC | 15' at 440degC | 5h at 440degC |
| Average size of crystals (nm) | -      | -             | 7+-1          | 11+-1          | 18+-1         |

Caption: Parameters of the heat treatments carried out on the samples and mean size of the PbF2 nanocrystals obtained by the analysis of the low-frequency-Raman spectra

You are provided with a table from a material science paper. Here are JSON templates for two types of numeric cells: "Other" and "Glass_Compound_Amount":
{"value": "xx", "type": "Other"}
{"value": "xx", "type": "Glass_Compound_Amount", "constituent": "xx", "unit": "xx", "material": "xx"}

Please describe all numeric cells in the above table following the JSON templates (proceeding by row in a left-right, top-down direction). For each cell, output one JSON description per line. For any unanswerable attributes in the templates, set their value to the placeholder "xx".

Cell Description:
{"value": "0", "type": "Other"}
{"value": "7", "type": "Other"}
{"value": "11", "type": "Other"}
{"value": "18", "type": "Other"}