Voids

Void or Space or Holes:

Empty or vacant space present between spheres of a unit cell, is called void or space or hole or interstitial void. When particles are closed packed resulting in either cpp or hcp structure, two types of voids are generated:

· Tetrahedral voids

· Octahedral voids

Tetrahedral voids:

Tetrahedral voids are holes or voids surrounded by four spheres present at the corner of a tetrahedron. Coordination number of a tetrahedral void is 4.

R(void)=0.255 × R(sphere)

Octahedral voids:

Octahedral voids are holes surrounded by six spheres located on a regular tetrahedron. Coordination number of octahedral void is 6.

R(void)=0.414 × R(sphere)