Crucibles and their selection

Crucibles and their lids are made of materials resistant to high temperatures, usually porcelain or an inert metal. Ceramics such as alumina, zirconia, and especially magnesia will tolerate the highest temperatures. One of the first metals used in crucible production was platinum; more recently, metals such as nickel and zirconium have also been used. The type of crucible used for thermoanalytical measurements can have a strong influence on the measurement results obtained. Additionally, the crucible can also influence the characteristics of the instrument’s measuring cell.

The measurements shown here on indium in Al, Pt, stainless steel and Al2O3 crucibles clearly demonstrate that both the thermal conductivity and the mass of the crucible have an effect on the DSC and DTA peak shape.
The calibration procedures take these effects into consideration and eliminate the influence of the crucible material on the measurement results.