Chemical analysis of the BaYxSn1-xO3-x/2 samples was performed on a spare set of discs which had not been calcined. Samples from these (~10mg) were digested in Parr vessels at 200 °C for 8 hours using 5 cm 3 of 38% HCl. The solutions were diluted to 50 cm 3 giving concentrations of Ba, Y and Sn of the order of 10 -100 ppm which were determined using ICP-OES. The metal insert (3mm brass sheet) keeps the bottom of the samples flat which is important for the X-Ray Diffraction analysis. The lower silicone part is made by casting a two-part room temperature curing silicone resin (DWR Plastics, TF10 7TP, UK Silicone Moulding Rubber Shore Hardness: A28) into a mould made using a PET sample tray and the brass insert, arranged so that the tray can be removed but the brass insert is retained within the silicone. The upper silicone layer can be a 2mm silicone sheet or a cast piece.