I am very grateful to you sir. Your way of explaining things is extremely simple and easily understandable. I feel like touching your feet sir. Great great great video
The maximum size of 0.225 r allows the four souurounding atoms to touch each other. In diamond they do not touch and are separated. Only the central atom touches these four atoms.
If you take the corner atoms and the face entering atoms of all the unit cells (ignoring the 4 inside atoms sitting on the body diagonals) their centres form an FCC lattice. Now if you consider the 4 inside atoms of all the unit cells, their centres also form an FCC lattice. The two FCC lattices are shifted by a/4 along a body diagonal.
About Diamond cubic crystal: sir, can we say like this "some of Carbon atoms have occupied tetrahydral void spaces" in fcc. Pls. Give some reference if psbl. of "lattice points" arrangement of diamond. Not cubic structure or tetrahydral structure.
Location wise yes. The four atoms inside the unit cell located at the body diagonal of the cube are located at the sites of tetrahedral voids in CCP structure. But two things should be noted. First, only half the voids are occupied. And second, the atom in the void is of the same size as the atoms defining the void.
@@introductiontomaterialsscience is this the same structure that we obtain in zinc blende structure (disregard the size difference of cations and anions )?
Respected Sir, Kindly share if you have done any videos about the packing factor of diamond. Also it would be nice to know a general correlation between atomic packing factor and hardness of different material.
I do not think there will be any direct relation between hardness and packing factor. Diamond is an example. It is one of the hardest materials but its packing fraction (0.34) is only half of that of a monatomic bcc crystal (0.68).
Teaching cannot get better than this.
charan kha h aapke...shat shat naman h aapko....what a teacher you are....hats off
Thank u so much sir its very very useful for my seminar
Thank you sir for this painful and patientful job
thanks for teaching....
really awesome
very nice explanation.
I am very grateful to you sir. Your way of explaining things is extremely simple and easily understandable. I feel like touching your feet sir. Great great great video
thank you, professor. Your explanations are just amazing.
Awesome explanation. But in Europe, we call them basis not motif. Basis is the international representation.
Thanks.
@@introductiontomaterialsscience tremendously explained...
Nice .Thank u
Thank you so much.
sir please tell me in different allotropes of carbon which structure forms which kind of voids(octahedral,tetrahedral)??
thus this motif is same as basis or not..
very helpful video thanks sir...
Yes, basis and motif are synonyms.
Prof, are these lectures on crystallography enough to get started with superconductivity?
It depends upon how much crystallography you need for your problem. What I have taught here is basic crystallography.
👍
Prof, hi. Why we consider firstly diamond as FCC ?
How many corners does a diamond have??
How can a carbon atom fit inside the void when maximum size of atom that can fit inside it is 0.225 r
The maximum size of 0.225 r allows the four souurounding atoms to touch each other. In diamond they do not touch and are separated. Only the central atom touches these four atoms.
what does it mean by two interpenetrating fcc make a diamond lattice?
If you take the corner atoms and the face entering atoms of all the unit cells (ignoring the 4 inside atoms sitting on the body diagonals) their centres form an FCC lattice. Now if you consider the 4 inside atoms of all the unit cells, their centres also form an FCC lattice. The two FCC lattices are shifted by a/4 along a body diagonal.
@@rajeshprasad101 thank you very much sir, superb explanation.
Ty very much sir
Very helpful !
About Diamond cubic crystal: sir, can we say like this "some of Carbon atoms have occupied tetrahydral void spaces" in fcc.
Pls. Give some reference if psbl. of "lattice points" arrangement of diamond.
Not cubic structure or tetrahydral structure.
Location wise yes. The four atoms inside the unit cell located at the body diagonal of the cube are located at the sites of tetrahedral voids in CCP structure. But two things should be noted. First, only half the voids are occupied. And second, the atom in the void is of the same size as the atoms defining the void.
Surya Prakash Goud !
@@introductiontomaterialsscience is this the same structure that we obtain in zinc blende structure (disregard the size difference of cations and anions )?
The atoms occupy only the upright tetrahedron voids.
Sir, why is diamond cubic structure not included in bravais lattice?
Even in Streetman(Solid state electronic devices) it is written as diamond cubic lattice...
I hope you agree with me that it is an incorrect usage.
@@introductiontomaterialsscience Sir please explain how to write motif or basis, it is confusing 🤦🏼♂️
Respected Sir,
Kindly share if you have done any videos about the packing factor of diamond. Also it would be nice to know a general correlation between atomic packing factor and hardness of different material.
I do not think there will be any direct relation between hardness and packing factor. Diamond is an example. It is one of the hardest materials but its packing fraction (0.34) is only half of that of a monatomic bcc crystal (0.68).
@@rajeshprasad101 Respected Sir,
Thank you very much for the reply.
Thank you