Packing Efficiency of Close Packed Structure - 1
Both ccp and hcp are highly efficient lattice; in terms of packing. The packing efficiency of both types of close packed structure is 74%, i.e. 74% of the space in hcp and ccp is filled. The hcp and ccp structure are equally efficient; in terms of packing.
The packing efficiency of simple cubic lattice is 52.4%. And the packing efficiency of body centered cubic lattice (bcc) is 68%.
Calculation of pacing efficiency in hcp and ccp structure:
The packing efficiency can be calculated by the percent of space occupied by spheres present in a unit cell.
Let the side of an unit cell = a
And diagonal AC = b
Now, in ∆ ABC,
AB is perpendicular, DC is base and AC is diagonal
Thus,packing efficiency of hcp or ccp structure=74%
Packing efficiency of body centered cubic (bcc) structure:
In body centered cubic unit cell, one atom is present in body center apart from 4 atoms at its corners. Therefore, total number of atoms present in bcc unit cell is equal to 2.
Let a unit cell of bcc structure with side a.
Let FD (diagonal) = b and diagonal AF = c
Let the radius of atom present in unit cell = r
Now, in ∆EFD
After subtituting the value of a from equation (vi) we get
Thus,packing efficiency of bcc structure=68%
Solid State - Introduction
Solid State - Crystal Lattice
Solid State - Close Packing Structure
Solid State - Efficiency of Close Packing Structure - 2
Solid State - Imperfections in Solids - Crystal Defects
Solid State - Electrical and Magnetic Properties
Solid State - NCERT In Text Solution 1
Solid State - NCERT In Text Solution 2
Solid State - NCERT In Text Solution 3
Solid State - NCERT Exercise Solution (Part 1)
Solid State - NCERT Exercise Solution (Part 2)
Solid State - NCERT Exercise Solution (Part 3)
Solid State - NCERT Exercise Solution (Part 4)
Solid State - NCERT Exercise Solution (Part 5)