Thermal Analysis
With the available STA device from Netzsch, various thermal and thermodynamic properties of materials can be investigated. Beside the characterization of materials and quality control, the determination of thermodynamic data is a central area of application. The system combines different measuring methods, which enables the processing of a multitude of different problems.
Three different measuring methods can be used. Thermogravimetry (TG), i.e. the determination of the mass loss of the sample, is always active in principle and is combined with a further method. Using an integrated balance with a resolution of 0.1 µg, the smallest mass changes can be detected. Thermogravimetry is used, for example, to determine water losses or temperature resistance.
Another method is differential thermal analysis (DTA). Two identical crucibles are used and the temperature difference between the sample and the so-called reference is considered. Depending on the measurement, different reference materials can be used, whereby the reference crucible usually remains empty. Thus, only sample effects are measured and the influence of the crucibles is eliminated. DTA is mainly used to determine characteristic temperatures (e.g. glass or melting temperatures).
| Manufacturer: | NETZSCH-Gerätebau GmbH |
|---|---|
| Model: | STA 449 F3 Jupiter |
| Furnace: | Platin furnace (25°C - 1500°C) |
| Heating / cooling rate: | < 5K/min - 50 K/min |
| Weighting range: | 35.000 mg |
| TG-Resolution: | 0,1 μg |
| DSC-Resolution: | < 1 μW |
| Analysis capabilities: | TG, TG-DTA, TG-DSC |
| Ambience: | Vacuum (1E-4 mbar), primary Argon (other gases also possible) |
The last method, Differential Scanning Calorimetry (DSC), is very similar to DTA in principle and design, but with a much higher sensitivity. This results from smaller crucibles on the one hand, which also results in a reduced maximum sample mass, and on the other hand from a larger sensor surface. With the help of DSC, specific heat capacities as a function of temperature can be determined in addition to melting points and e.g. mixing, reaction and transformation enthalpies.
The combination of thermogravimetry with one of the two differential methods leads to simultaneous thermal analysis (STA).
Depending on the sample material requirements, both the gas atmosphere and the crucible materials used can be varied. In addition to various gases (mainly argon), measurements can also be carried out under permanent vacuum.
A variety of ceramics (e.g. Al2O3, Y2O3) as well as various metals (e.g. Al, Au, Pt/Rh) and combinations thereof are available as crucible materials. These adjustments are necessary to prevent contamination or reaction between the crucible and the sample.
The modular design of the system enables quick conversion, which guarantees optimum adaptability to the required measuring conditions at all times. At present, for example, electrode materials of modern Li-Ion batteries are in the focus of investigations.