Octahedral Void Or Tetrahedral Void Flashcards
FCC KE UNAR KITNE NO. OF VOIDs PRESENT HAI
8 tetrahedral void
Can u explain how 8 tetrahedral voids present
If one fcc cube is cut in to 8 cubes then each centre of cube has 1 tetrahedral void
How many octahedral voids present in a unit cell
1 octahedral voids at body centa
12 at edge centre [ ye Jo edge pr laga hoga void wo share ho rha hoga 4 unit cell se to 1 unit cell me Iskandar contribution 1/ 4th hee hoga to total no. Of octahedral void has one unit cell is 3
Means 4 octahedral voids
Body centre
1x1=1
Edge centre
12x1/4=3
4Oĥ
In fcc
Atoms
Td
Oh
4 Atoms
8 T voids
4 OH voids
In BCC
Atoms
Td voids
Oh voids
2
4td
2Oh
In SCC
Atoma
Td voids
Oh voids
1
2Td
1Oh
NaCl is type of unit cell
Na+ occupy
Cl- occupy
CN
FCc unit cell
Od voids na+=4
Cl- lattice points =4
So formula Na4Cl4=NaCl
Ionic distance = a/2
CN. 6
AB type
ZnS ( zinc blende)
Unitcell
Zn+2
S2-
CN
Type
FCC
4 td voids
4
4
AB
a x root 3/4
CsCl
Unit cell
Cs+
Cl-
CN
Type
Internuclear distance
SCC
Cs+ =1 cubic void
Cl- = 1
CN = 8
AB
ax root 3/2
Na cl
ZnS
CsCl
6
4
8