1. How to estimate grain crystal size by fitting?
Answer: (1) This function in the peak fitting, select one or several diffraction peaks to fit, the premise is to do a standard instrument curve, select the appropriate background curve, peak function, etc., so that the estimated grain size will be more accurate.
(2) The "Kα2" function in the mouse function can be used to fit the grain size by rolling the wheel of the mouse. As shown by the diffraction peak at 25.3° in the figure below, a standard peak shape function is required.
(3) There is another method in JADE, which can separate the grain size from the half-height width caused by strain. Under the function of fitting peak, all the diffraction peaks in the XRD pattern are fitted to check the analysis results of grain size and strain.
2. In the process of quantitative analysis of multiple phases, how to distinguish the peak position of overlapping phase?
Answer:(1) JADE distinguishes the corresponding diffraction peaks of different objects through different colors;
(2) In JADE, the results of peak fitting of diffraction peaks of different phases can be displayed, and different colors are also used to distinguish.
(3) The diffraction peak fitting of a certain phase can be displayed single-phase in JADE
3. If refined, what are the requirements for XRD data?
Answer:(1) The sample has good crystallization and sharp diffraction peak;
(2) The sample has no significant preferred orientation problem;
(3) Accurate Angle information;
(4) The diffraction peak count is high (the strongest peak count is better than 10,000), and the data statistics are good;
(5) The range of angles collected is as large as possible (2theta is generally not less than 120° for copper targets) so that as much high-resolution diffraction data as possible is included in the finishing process.