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DIL L75 VS – Quarz – Thermal expansion – calculated DTA

Quartz Sample – Thermal expansion / quartz transformation / phase transition / calculated DTA

The thermal expansion of SiO2 can be easily measured by L75 dilatometer including the phase transition from quartz to quartz. Single crystal quartz shows a phase transition into so called high quartz (quartz) at around 575°C which can be detected by expansion measurement. Additionally, the calculated DTA feature of the Linseis L75 dilatometer series enables an in-depth view of the thermal behavior of the material and easy detection and identification of such phase transitions. The calculated DTA measurement is a mathematical routine based on the sample temperature. Exo- and endothermic effects influence the change of the sample temperature during the dynamic heating or cooling cycle in comparison to the set heating profile.

App. Nr. 02-001-003 DIL L75 VS – Quartz – Thermal expansion – calculated DTA

App. Nr. 02-001-003 DIL L75 VS – Quartz – Thermal expansion – calculated DTA

The phase transition of the measured α-SiO2 takes place at app. 575°C. The blue curve shows the measured absolute delta-L value vs. temperature in µm which is the standard signal a dilatometer shows. The red cal-DTA curve of the measurement is generated by a mathematical evaluation of set temperature and actual sample temperature. It shows a peak that indicates the phase transition like a classic DSC or DTA would show. Applying the DTA feature enables to determine the exact phase transition temperatures in case the expansion curve does not provide a definite onset point.

The deviation of the measured temperature (575.8°C) from the literature value (574°C) can be used for a temperature calibration.

Related instruments

DIL L75

  • Vertical “Zero-Friction” Dilatometer
  • Multi furnace option (up to 3 furnaces)
  • Different furnaces: -263 up to 1000/1600/1750 …2800°C
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