1.

If the radius of the octahedral void is r and radius of the atoms in close-packing is R, derive relation between r and R.

Answer»

Solution :The relation between R and R for OCTAHEDRAL void is derived as under :
A sphere fitting into an octahedral void is shown in the Fig. For CLARITY, the spheres above and below have been REMOVED. ABC is a right angled triangle.
`therefore""BC^(2)=AB^(2)+AC^(2)`
`"or"(2R)^(2)=(R+r)^(2)+(R+r)^(2)=2(R+r)^(2)`
`"or"((2R)^(2))/(2)=(R+r)^(2)`
`"or"(2sqrt2R)^(2)=(R+r)^(2)`
`"or"R+r=sqrt2R`
`"or"r=sqrt2R-R`
`"or"r=R(sqrt2-1)`
`"or"r=0.414R`


Discussion

No Comment Found