I am working on laser. I use laser to irradiate the amorphous material, then I would like to know how many percent of crystalline phase created in amorphous? Is it possible to calculate the degree of crystalline phase after laser heating by using DSC ?
Yes, it is possible if the crystalline phase produced melts during heating and if you know the enthalpy change of the full crystalline sample. In this case you can compare the enthalpy change values.
Hi Nguyen, Yes it is possible to use DSC semi-quantitatively for the purpose in question.
If you want to determine the amount of crystalline phase, then you will need to generate a calibration curve. For this you will need to prepare a mixture of known quantities of the amorphous and crystalline material. There are two ways you can generate a calibration curve for your particular work; (1) you can use the step change in baseline at the glass transition upon heating for known quantities of the amorphous material in the mixture or (2) you can use the heat of fusion value for known quantities of the crystalline material in the mixture. You can then determine the amount of crystalline phase present in your treated samples using the equation from the calibration curve.
You may experience some challenges in generating a good calibration with this method e.g the crystalline content in the mixture may increase disproportionately if the amorphous material crystallizes past the Tg. Also the limit of detection/quantification of the DSC may not be very good. So for these reasons I think it would be better to use X-ray powder diffraction.
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