The quality of the platinum dishes used is crucial for the successful fusion. A platinum gold alloy with 95% platinum and 5% gold is used as the crucible material. The gold has the function of making the platinum mechanically more stable and reducing the wettability of the surface by the melt. There is also a special alloy FKS platinum. Small additions of zirconium harden the platinum, serve to refine the grain and strengthen the structure of the Pt alloys. This increases the service life compared to pure platinum gold alloy.
For the fusion process a crucible for receiving the mixture of the sample with melting agents is needed. It is important that the crucible is large enough to avoid spilling over while stirring. For some samples, the addition of additives such as oxidizing agents is necessary. It must be taken into account that there must be enough space in the crucible for the chemical reaction. Different crucible sizes are available for the VITRIOX® fusion machines.
The dissolved sample material is poured into a mould. Its size must correspond to the cassette used in the XRF. Glass beads with a diameter of 29 to 40 mm are common.
As an option, the crucible in the VITRIOX® ELECTRIC can be provided with a lid, for example to reduce the volatility of elements.