Compounds having frenkel defect conduct electricity to a small extent. When electric field is applied, an ion moves from its lattice site to occupy a hole, it creates a new hole. In this way, a hole moves from one end to the other. Thus, it conducts electricity across the crystal. Due to the presence of holes, stability (or the lattice energy) of the crystal decreases.
Both naturally-occurring and artificial quartz crystal contains at least ninety-nine percent silicone dioxide, while cut glass crystal only possesses at most eighty percent silicone dioxide.
Potassium, rubidium.
In an alloy of gold and cadmium, gold crystallizes in cubic structure occupying the corners only and cadmium fits into the face centre voids.
Number of gold atoms =1/8 x 8 =1Au
Number of candium atoms =1/2 x 6 =3Cd
Hence, quantitative composition on = AuCd3
When doping a semiconductor, such as the group IV element silicon (Si), with arsenic (As), a pentavalent n-type dopant from group V in the periodic table the dopant behaves as an electron donor.