I have performed XRD of CeO2 and used TOPAS for calculation of microstrain. I followed the procedure exactly mentioned in the TOPAS manual but could draw conclusion from the study
Carful with the numbers, they contain a factor! The numbers from the Strain_G and Strain_L commands contain from my present knowledge still the infamous 180°/pi factor. Use the e0_from_Strain reporting command.
Attention. The e0_from_Strain works correct in TOPAS5. But in topas4.2 I have also still running, there is still the 180°/pi factor also for the e0_from_Strain!!!
I quite agree with Dr. Leineweber.
Another option is use MAUD software.
Best of luck.
The nice things about TOPAS is that you can check and modify the macros by yourself. Thus you are yourself responsible what refined parameters you publish....
Thank you Lucas and Andreas for your suggestions. Your suggestions would definetly help me strain calculation.
As always in evaluation of microstructure the reliability of a specific parameter depends on the quality of the model and the specific type of sample. If the instrumental intensity distribution was parametrized well, a large 2theta range was used and crystallite size was taken into account, then strain may be discussed. Which effect is the main effect? Crystallite size or strain? If the Rwp does not change significantly if you ignore strain (no strain parameter used) compared with a model including strain, then also the value yielded for strain is not reliable or "siginifant". This is valid especially if a model with or without taking crystallite size provides significant or bigger differences in Rwp. The CeO2 samples I evaluated long a time ago had crystallite size as the dominant effect.
Ravikumar Iyyamperumal I have explained it in OriginLab
When a deviation from the ideal crystalline occurs, XRD peak broadening takes place. This broadening can be instrumental as well be due to the nature of the sample. When it comes to the sample, it may be mainly due to the crystallite size, microstrain, solid solution inhomogeneity, and temperature factors. Among these, microstrain is a dominant factor, which is defined as the root mean square of variations in the lattice parameters across the sample. The microstrain itself depends on the non-uniform lattice distortions, faulting, dislocations, antiphase domain boundaries, and grain surface relaxation.
In the following 11 min video, I have explained in detail the microstrain and how to calculate it from XRD data. In the first 5 min, I have first explained 'what is meant by the microstrain '. In the next 6 min of the video, I have taught 'how to calculate the microstrain from XRD data in origin. If you need anything further to ask, let me know. I'll appreciate your feedback on the video tutorial. I have attached the discussed files (Origin file and Excel template) here, as well as, they can be accessed from the description in the video. Thanks
How to calculate microstrain from XRD data using origin
https://youtu.be/oUwJpGtwOVk
Ravikumar Iyyamperumal In this video tutorial, I have explained in detail how and how to calculate lattice constants for cubic and orthorhombic structures from the XRD data using OriginLab software. When a deviation from the ideal crystalline occurs, XRD peak broadening takes place. This broadening can be instrumental as well be due to the nature of the sample. When it comes to the sample, it may be mainly due to the crystallite size, microstrain, solid solution inhomogeneity, and temperature factors. Among these, microstrain is a dominant factor, which is defined as the root mean square of variations in the lattice parameters across the sample. The microstrain itself depends on the non-uniform lattice distortions, faulting, dislocations, antiphase domain boundaries, and grain surface relaxation.
We can't calculate microstrain from all types of XRD data (samples). There're surely limitations in these calculations. Here one can understand briefly what is microstrain and how to calculate it correctly from XRD data. In the case you want to further ask about it, please do comment on the specific video, I'll respond to it shortly. I have provided the practice as well as calculations files here. Thanks
In the following 11 min video, I have explained in detail the microstrain and how to calculate it from XRD data. In the first 5 min, I have first explained 'what is meant by the microstrain '. In the next 6 min of the video, I have taught 'how to calculate the microstrain from XRD data in origin. If you need anything further to ask, let me know. I'll appreciate your feedback on the video tutorial. I have attached the discussed files (Origin file and Excel template) here, as well as, they can be accessed from the description in the video. Thanks
How to calculate microstrain from XRD data using origin
https://youtu.be/oUwJpGtwOVk