Environmental Engineering Reference
In-Depth Information
Figure 5.9
(a) Schematic illustration of Schottky disorder with doubly charged vacan-
cies, V
M
and V
•
X
in a compound, MX. (b) Schematic illustration of Frenkel disorder involv-
ing doubly charged cation vacancies and interstitial ions in a compound, MX.
illustrated schematically in Fig. 5.9a. Systems showing predominantly this type
of disorder are KCl, NaCl, PbI
2
, PbCl
2
etc. AgCl near its melting point shows
almost 5-10% of Schottky defects.
Frenkel Disorder
A crystal with Frenkel disorder contains the same concentrations of vacancies
and interstitial ions for the same kind of atom. A schematic illustration of this
