If you would like to utilize the Diffraction Facility for data collection and/or analysis, please reach out to Michael Koehler at mkoehler@utk.edu.

I am a postdoc. This was one of the best xrd lectures I’ve ever seen Great work

This is a really good video on XRD. Extemely underrated.

Today is my phd interview and I really needed to understand the fundamentals of XRD. Thank you so much Sir for explaining it with such fluidity❤❤.

Thank you for your effort in making videos which are helpful to students and teachers all over world . ❤️

@IAMMDiffractionFacility

3 жыл бұрын

That is so nice of you to say! I really appreciate it :)

Very helpful information as we are purchasing SEM n EBSD

@IAMMDiffractionFacility

Жыл бұрын

Glad it was helpful!

Wow, after three years, Now I understand how XRD works,, I don't know how to thank you man

@IAMMDiffractionFacility

3 жыл бұрын

I'm happy to hear that! And honestly, comments like yours mean more to me than I can say and encourage me to continue making videos, so thank you.

Thanks, I enjoyed watching this video

@IAMMDiffractionFacility

Жыл бұрын

Glad to hear it!

Thanks for your video. Very informative

@IAMMDiffractionFacility

3 жыл бұрын

Thank you, I'm glad it was helpful!

i am having my soil state exam tommorow thank youuu so much

@IAMMDiffractionFacility

8 ай бұрын

I hope it went well!

very clear , excellent thank you

Wonderful explanation Thank you very much

@IAMMDiffractionFacility

3 жыл бұрын

I'm glad it was helpful!

Is it possible for you to upload or distribute the original slides? I would really like to utilize some of the diagrams/figures you have used in this wonderful presentation.

Good stuff! Thanks

when it comes to bragg low i thought it is some kind of gfferent thing it is so supprising to see it is just all about constructive and distrctive interfernce

Sir why do crystals have inter planer spacing?

This was really helpful!! I have a question regarding GIXRD measurement. If I am not wrong, GIXRD is used to study the crystal arrangement of samples at different depths. Is GIXRD similar to in-plane XRD or is it different? Also, does GIXRD give any information regarding the plane perpendicular to the substrate?

@IAMMDiffractionFacility

2 жыл бұрын

Thank you for the kind words! And I apologize for the slow response, I was very busy preparing for and then taking a vacation. Regarding your question, let me direct you to this paper from Rigaku (www.rigaku.com/newsletters/mabu/pdf/TF4_In-Plane.pdf). This does a better job explaining these concepts with pictures than I could do using only words here in the comment section.

What happens if the diffraction angle was 180 degree?

@IAMMDiffractionFacility

Жыл бұрын

That would mean that the X-ray source and detector would occupy the same physical space. This is what limits us in how high in 2theta we can collect data.

This is damn good! Well done...

@IAMMDiffractionFacility

3 жыл бұрын

Thanks!

At 6:02 I was just wondering why n can be ignored for calculation purposes? Other than that I thought it was a great video and it helped a lot, gave it a like. PS sorry if you've had to answer this question already.

@IAMMDiffractionFacility

3 жыл бұрын

I suppose "ignored" was the wrong term to use. In reality, we are just assuming it is 1. Essentially, (hkl) studied at a value of n other than 1 gives the same results as using n = 1 for the (n*h n*k n*l) plane. For that reason, we can just assume that n = 1 for each plane. Personally, I like to work things out with numbers to see how it works. If you are similar, let's imagine that we are studying TiO2. For the (101) plane, d = 3.51455 angstroms. Let's also assume that we are using Cu Kalpha radiation (lambda = 1.5406 angstroms). If we use n = 1 and enter the values listed above for the wavelength and d-spacing, Bragg's law looks like (1)*(1.5406) = 2*(3.51455)*sin(theta) Solving for theta and multiplying by 2 (since peak locations are reported in 2theta), we get 25.321 degrees. If we do the same thing but make n = 3, we get a 2theta value of 82.222 degrees. Let's now see what happens if we look at the (303) plane, which has a d-spacing of 1.17152 angstroms. If we choose n = 1, we get (1)*(1.5406) = 2*(1.17152)*sin(theta) Solving for theta and multiplying by 2, we get 82.222 degrees, which is the same value we obtained when looking at the (101) plane with n = 3. This shows that n=3 for (101) gives the same results as n=1 for (303). I hope that makes sense!

@neroscr7

3 жыл бұрын

@@IAMMDiffractionFacility that’s incredible, thanks for your rapid response with a great walkthrough! ❤️

2:00 previous knowledge about miller indices for surfaces needed

does DNA behave the same way?

Sir IAM prepare for jee that question asked in McQ

why do we call it a diffraction phenomena when its just reflection and constructive interference occurring?

@IAMMDiffractionFacility

Жыл бұрын

The simplified way of looking at a diffraction experiment and explaining Bragg's law makes it look like it is just reflection, but it isn't. What XRD makes use of is elastic scattering, in which the X-rays begin oscillating the electrons in atoms. Those oscillations then release X-rays of the same wavelength as the X-rays that cause them. These new X-rays are what leave the sample.

@jayjain1033

Жыл бұрын

@@IAMMDiffractionFacility shouldn't a photon of x ray have enough energy to dislodge an electron from the atom. or do these crystals have very high binding energy to their electrons? And don't electrons only absorb a photon if its energy can allow the electron to do an energy level transition otherwise they just let the photon pass? Or is this a misconception i have

@IAMMDiffractionFacility

Жыл бұрын

Very good questions. Let me preface my thoughts with the admission that it has been many years since I have really thought on these topics in such depth. Most of my work with X-rays and whatnot has been more practical (setting up experiments, analyzing data, etc.), so I've likely lost some of the knowledge I used to have on such topics. Sometimes, the X-ray does have enough energy to dislodge an inner-shell electron from the atom. Such a situation is how you get very undesirable fluorescence in your diffraction patterns when using certain X-ray sources to study samples with certain elements (e.g., Cu source strongly fluoresces Co and Fe). I can't explain why, but this problem seems to strongly occur for only two or three elements that depend upon the type of source you are using. Regarding absorption of a photon, it is my understanding that moving/removing an electron from its shell (see previous paragraph) and oscillating electrons are two options.

@jayjain1033

Жыл бұрын

@@IAMMDiffractionFacility ok thank you for your help! I've tried looking for deeper answers to these questions but have struggled to find anything concrete online😅

Thanks for your video. I have a question from the Laue Experiment. There are different kinds of dots (from the diffraction peaks) some of them are very clear and others are diffusive. Is there some explanation for this occurrence?

Can somebody solve my doubt. We can calculate d-spacing from bragg's law but how can we calculate the lattice parameters and lattice angles because once we know d-spacing, a,b,c and alpha.beta abd gamma, we can know if it is FC,BC or primitive latttice. Please explain this to me.

@IAMMDiffractionFacility

3 жыл бұрын

Have you ever heard of indexing peaks? If you search KZread, I'm sure you can find some examples. Essentially, different types of unit cells have certain allowed and forbidden reflections (see here for some examples: groups.mrl.uiuc.edu/chiang/czoschke/diffraction-selection-rules.html) based off of symmetry/geometry. What this means is that peaks from certain planes will appear, peaks from certain planes won't appear in the pattern. Different types of symmetry have different equations to explain the relationship between the d-spacing and the lattice parameters. You can use the 2theta positions of the peaks to solve Bragg's law for the d-spacings of the peaks, and then you can use the d-spacings to solve for the lattice parameters. This might require some trial and error as you first have to assume a crystal structure and use that assumption to solve for the lattice parameters. If a single set of lattice parameters works in conjunction with your assumed crystal structure, then you are likely good. If a single set of lattice parameters doesn't work, then your assumption of the crystal structure is likely incorrect, and you need a new assumption. This is much easier to understand when shown rather than told, which is why I suggest looking up a video on indexing. The math isn't all that difficult, assuming that you don't have a very low-symmetry structure, it is just a bit time consuming to work everything out.

superb

Subtitles are covering the picture.. hard to follow

@IAMMDiffractionFacility

3 жыл бұрын

My apologies. I originally made this to be presented during a seminar. I then simply uploaded it to KZread, not really thinking about subtitles.

Nice

@IAMMDiffractionFacility

3 жыл бұрын

Thanks!