Material and method of fabrication therefor
The present invention concerns new methods of fabricating a silicon material comprising phosphorus. The methods allow high levels of phosphorus to be combined with the silicon. In one aspect of the invention a sample of phosphorus is surrounded with a sample of silicon. At least some of the phosphorus is then vaporised and caused to interact with the silicon.
1. A method for producing a composite material comprising phosphorus and silicon, the method comprising the steps:
(a) taking a sample of phosphorus;
(b) substantially surrounding the sample of phosphorus with a layer of silicon, the layer of silicon comprising a multiplicity of silicon particles;
(c) applying heat to the silicon in such a manner that a temperature difference is established between at least part of the silicon layer and the sample of phosphorus, and in such a manner that at least some of the phosphorus is vaporised; and
(d) allowing and/or causing between 80% and 100% of the phosphorus vapour to contact at least part of the layer of silicon in such a manner that a molten composite material comprising silicon and phosphorus is formed.
2. A method according to claim 1 characterised in that steps (a), (b), and (c) are performed in such a manner that at least part of the silicon layer is heated to a silicon reaction temperature between 900 C and 1500 C.
3. A method according to claim 1 characterised in that the sample of phosphorus comprises red phosphorus.
4. A method according to claim 1 characterised in that method comprises the further step (e) of atomising at least part of the molten composite material generated by step (d).
5. A method according to claim 4 characterised in that the method comprises a further steps: (fi) of cooling and then (fii) porosifying at least some of the composite material formed by step (e).
6. A method according to claim 5 characterised in that the method comprises the further step (g) of irradiating at least some of the composite material produced by (fii) with neutrons in such a manner that at least some of the phosphorus is converted to 32 P.
7. A radiotherpeutic product obtainable by a method according to claim 6 .
8. A radiotherapeutic product according to claim 7 for use in the treatment of cancer.