I agree with you: Clear and concise lecture! By the way, the probability for me to find a comment from a former IFM "colleague" on a youtube lecture video was quite low :) Make steel strong again
Nicely explained. Best lecture ever. We can throw these solid state physics books away that keep talking about Fourier analysis because it is simply not practical.
Thanks very much for your vedio. At 10:06, your vocal "2theta angle" in fact means the "theta" angle right? as the angle between incident beam and the plane normal (230) should be 90-theta...
You are exactly right! mis-speak on my part. at 8:30, the angle you're talking about is identified as "theta". So used to thinking about diffraction results, which we usually plot in terms of "2 theta"...
Hi ! This was really clear thanks. I have a question: Why doest the screen detect the constructive interference only when the points intersect the Ewald's sphere ? Satisfaction of Bragg's law is something that happen depending on the structure of the crystal (In terms of phase and plane distance), but constructive interference is something that happen inside the 3D space beyond the crystal right ? How is this phenomenon related to Ewald sphere ? Sorry if i've not been very clear ☺️
Would it be accurate to think of reciprocal lattice points as imaginary apertures which, if passed through by a diffracted X-ray beam, correspond to observed diffraction spots?
Yes - this is absolutely fair. In fact, this is how a TEM works. You can place the detector at 1 position and image the diffraction pattern (i.e., a slice of reciprocal space), or you can position it differently to observe a microscopic image. AND, you can take an actual aperature and block out all your electrons except those passing through a specific diffraction point, and only use those electrons to make the image (this is called SAED, or selected area electron diffraction).
Hey great Video! I do not quite understand what is meant with the angle beta it just seems to be in the room and I am also not sure how to determine the direction of the second vector. Is it just the formula of reciprocal vectors?
Beta is the crystallographic angle (i.e., the angle between the two lattice vectors). This *could* be 90 degrees for a rectangular lattice, but does not have to be. We chose beta here because, by convention, the non-90 deg angle in a monoclinic lattice is beta.
This is THE best lecture on this topic! Thank you, Prof. Shamberger!
I agree with you: Clear and concise lecture!
By the way, the probability for me to find a comment from a former IFM "colleague" on a youtube lecture video was quite low :)
Make steel strong again
@@gilga03gig61 Howdy! Haha, good catch~ It's unfair that I don't know your name my fellow IFM mate...
the unique usefulness of UA-cam is that you can find smart and clear explanation of any abstract concept. Good job!
Great video! Hard to find good material on these subjects, glad i found this channel.
Nicely explained. Best lecture ever. We can throw these solid state physics books away that keep talking about Fourier analysis because it is simply not practical.
Very good and clear! Best i‘ve seen yet. Made some very important connections clear
Thank you so much Sir. This video really helped me to understand more about reciprocal space!!
very beautifully explained. thank you for your effort
A great video with simple words! Thank you very much.
Thank you so much for the clear explanation!
Thank you sir, I finally understood after 4 years of studying in material science...
A big thanks for super usefull content
Thanks very much for your vedio. At 10:06, your vocal "2theta angle" in fact means the "theta" angle right? as the angle between incident beam and the plane normal (230) should be 90-theta...
You are exactly right! mis-speak on my part. at 8:30, the angle you're talking about is identified as "theta". So used to thinking about diffraction results, which we usually plot in terms of "2 theta"...
@@pjshamberger thanks very much for the clarification. Your video has been really helpful to me
Thank you for the video.
Wow, thank you very much
Two minutes into this video I know this is good shit
Hi ! This was really clear thanks. I have a question: Why doest the screen detect the constructive interference only when the points intersect the Ewald's sphere ? Satisfaction of Bragg's law is something that happen depending on the structure of the crystal (In terms of phase and plane distance), but constructive interference is something that happen inside the 3D space beyond the crystal right ? How is this phenomenon related to Ewald sphere ? Sorry if i've not been very clear ☺️
Would it be accurate to think of reciprocal lattice points as imaginary apertures which, if passed through by a diffracted X-ray beam, correspond to observed diffraction spots?
Yes - this is absolutely fair. In fact, this is how a TEM works. You can place the detector at 1 position and image the diffraction pattern (i.e., a slice of reciprocal space), or you can position it differently to observe a microscopic image. AND, you can take an actual aperature and block out all your electrons except those passing through a specific diffraction point, and only use those electrons to make the image (this is called SAED, or selected area electron diffraction).
So, in the diffraction pattern, a bright spot will correspond to the family of planes?
How can you draw the 200 plane? There are no atoms on this plane?
Hey great Video! I do not quite understand what is meant with the angle beta it just seems to be in the room and I am also not sure how to determine the direction of the second vector. Is it just the formula of reciprocal vectors?
Beta is the crystallographic angle (i.e., the angle between the two lattice vectors). This *could* be 90 degrees for a rectangular lattice, but does not have to be. We chose beta here because, by convention, the non-90 deg angle in a monoclinic lattice is beta.
Vectors in reciprocal space are oriented perpendicular to planes in real space.
Thank you so much sir
howdy
Thank you soo much ❤