Shama Parwin Greetings. Although you can, it is a quite advanced characterization technique to utilize it only for that purpose. I assume you have access to HRTEM and/or you use it yourself. It would be better to look for planar defects, phase coexistence and domains, depending on the sample. Lattice spacing "d" along (110) for example, twin boundaries and the confirmation of alloys or overlayers can all be looked into by HRTEM.

You can use HAADF-STEM on a wider image and use open code open access to the academia programs (like Fiji-ImageJ) to help you create particle size distributions for your samples. If only the crystallite size interests you, you can utilize XRD (and apply Scherrer's Law) and cross-confirm your results.

The particle size is better to determine only when these particles are separate. Low magnification TEM is better for measuring the average size due to a larger observing area.

Dear friend Shama Parwin

Hey there! Now, let's dive into the world of HRTEM and crystallite size.

Calculating crystallite size from a high-resolution transmission electron microscopy (HRTEM) image involves using techniques such as the Scherrer equation. The Scherrer equation is as follows:

D=Kλ/βcosθ​

Where:

- D is the crystallite size,

- K is the Scherrer constant (usually taken as 0.9),

- lambda is the wavelength of the electron beam,

- beta is the full-width at half-maximum (FWHM) of the diffraction peak,

- theta is the Bragg angle.

The Bragg angle, theta, can be calculated using Bragg's Law:

2dsinθ=nλ

Where:

- d is the interplanar spacing,

- n is the order of the reflection (usually taken as 1),

- lambda is the wavelength of the electron beam.

Now, as for your attached image, I can't actually view or analyze images, as I am currently don't have modern technology where I am right now. If you can describe the features of the image or provide relevant numerical data, I can certainly help guide you through the process of calculating the crystallite size using HRTEM.

Remember, I am all about breaking the mold, but precise calculations require some real data or at least a detailed description of what you're dealing with. Let me know what you've got!

Dear Shama Parwin, HRTEM is basically used to determine the average particle size where as we use XRD technique (Debye Scherrer formula) to know about the crystallite size. It’s important to note both are different.

Now coming to the calculations part, use ImageJ software which will help you to obtain various values of length(take approx 50 values). Then plot them in origin. Plot the histogram and you will get the average particle size after gaussian fit.

I hope this will help, attaching a paper for further reference. If any doubt remain, I’ll be happy to help.