❖ <u>Packing Efficiency</u> ❖
➪ The percentage of total space occupied by particles is called <u>packing efficiency</u>.
❖ Packing efficiency of simple cubic structure (SCC).❖
❒ Since, simple cubic unit cell contain 1 atom (sphere). So, the total volume of sphere will be :
- Volume of unit cell = (2r)³
- Volume of unit cell = 8r³
❒ <u>Now, we know that</u>,❒
➪ Substituting the known values in the formula, we get the following results:
❒ Hence, the packing efficiency of simple cubic structure is 52.4%.
➪ Packing efficiency of cubic close packing (SCC)/face centred cubic structure (FCC).
❒ Since, simple cubic unit cell contain 2 atom (sphere). So, the total volume of sphere will be:
Volume of unit cell = (2√2r)³
Volume of unit cell = 16√2r³
❒ <u>Now, we know that</u>,❒
➪Substituting the known values in the formula, we get the following results:
❖ Hence, the packing efficiency of face centred cubic structure is 74%.
❖ Packing efficiency of body cubic structure (BCC).
❒ Since, simple cubic unit cell contain 2 atom (sphere). So, the total volume of sphere will be:
Volume of unit cell = (4r/√3)³
Volume of unit cell = 64r³/3√3
❒ <u>Now, we know that</u>,❒
➪Substituting the known values in the formula, we get the following results:
❒ Hence, the packing efficiency of body centred cubic structure is 68%.