Try FullProf analysis. If the calculated concentrations of the components of the mixture will significantly differ from those indicated by you, then you need to start thinking ... In addition, particle sizes do not matter for XRD. The intensity depends on the size of crystallites (single crystal regions), which can either coincide with the particle size (rarely) or be much smaller than these.

this paper can help you

https://books.google.dz/books?id=TjQ4D7dHjKEC&pg=PA1&lpg=PA1&dq=How+XRD+intensity+is+affected+with+density+of+powders+?&source=bl&ots=qiPzClSqXR&sig=ACfU3U1D8lGnO2_XW35NHO2PD3P4Do4-ZQ&hl=fr&sa=X&ved=2ahUKEwiUrvOhuIvqAhXC7eAKHf4wDlMQ6AEwCnoECAoQAQ

Ashish Nayan

Intensity in XRD is notorious for being dependent on many things. In your case orientation of crystal planes, crystallinity, and atomic number (roughly correlates with density) are applicable and need to be considered. B4C has 2 very low atomic number constituents and will thus provide weak diffraction data.

BTW, I'm suspicious of an average particle size of 0.5 microns for a powder. How was this determined?

Dear@Alan F Rawle the size were measured with particle size analyzer.

Ashish Nayan There are at least 300 types of 'particle size analyzer'. What technique was used?

Try FullProf analysis. If the calculated concentrations of the components of the mixture will significantly differ from those indicated by you, then you need to start thinking ... In addition, particle sizes do not matter for XRD. The intensity depends on the size of crystallites (single crystal regions), which can either coincide with the particle size (rarely) or be much smaller than these.

Vadim S. Gorshkov Yes, I agree with you that particle size shouldn't matter for conventional (Debye-Scherrer) powder XRD as long as we have plenty of random orientation of crystal planes (and micronization of larger material is often used to achieve this). Obviously smaller crystallite sizes broaden the peak (Scherrer equation) . My later concerns were with the original statement in the line 'The average particle size of the same were 5.37μm, 8μm, 0.5μm, 2.5 μm respectively' followed by 'the size were measured with particle size analyzer':

• What is meant by 'average'? Number, volume/mass, intensity? x50, D[4, 3] etc
• '5.37 microns' implies a precision perhaps only seen with particle size standards from a CRM manufacturer such as NIST
• 0.5 microns average size is pushing the lower bounds for a powder
• The use of the term 'particle size analyzer' where anything from a Hegman gauge to an electron microscope could be labeled in this way. I usually expect a light scattering (laser diffraction) response here

Vadim S. Gorshkov

I was actually trying to answer the question and the misunderstanding of XRD (intensities) in the statement 'Logically B4C should show the highest intensity as it is the prominent phase'. This is actually not logical and is a very worrying comment.

This is the case when we do not need to think, but just need to count. Although the calculations are very voluminous.

Ashis

Don't see maximum intensity, see the area under the curve, I think your TiB2 is quite strained and therefore it is showing less intensity and more broadening. Your XRD needs to be background corrected, it is not showing a proper background where good comparison of peak heights can be done, you can always see the area under the peak and it appears to be TiB2 peak is mixed with some other compound , if you are having vacumm annealing facility or glass sealing facility, you pack your powder in a glass tube and then anneal it. thereafter take the XRD, now you see if your TiB2 is showing max intensity or not.

Density of the powder is depends upon the agglomeration of particles and its distribution as well as size. According to Zener pinning effect, the intensity of the peak is affected due to the movement of minimum and maximum angle grain boundaries when dispersion taking place.

D. Saravanak Kumar

You're talking of apparent density, I think. XRD calculates real density from the unit cell and chemical information. Most, if not all, introductory XRD texts will show this. Orientation of crystal planes is one important factor as I indicated very early on in this discussion.

Dear Mr. Nayan,

we are talking about relative (peak height) intensities, since comparison you did is from the same xrd pattern.

As mentioned above, peak height intensities can be missleading - much better is compare integrated (area under peak) intensities. This can change situation remarkably. Recommentadion to try FullProf is good one.

Each phase has own absolute intensities. It can be a case that minor phase gives stronger intensities. Even more - the same phase can give different peak height intensities depending on state of crystals. Well developed, stress and faults free crystals give higher peak height intensities. Of course, there is many other factors, as mentioned above. (Not to mention preffered orientation in powder sample :-)

So, do not be disturbed by a fact that minor phase gives stronger peak height intensities. It could be perfectly correct. Please, read some good books about XRD powder techniques.