
Specific Heats: Magnificent Bridges 113
FIGURE 5.2 Comparing Einstein and Debye theories.
case. Then the optical modes can be neglected, and integration yields the T
3
law for
specific heats. As already mentioned, the low temperature behaviour of the specific
heat of electron gas has a linear dependence in T, and therefore the Debye theory has
to be modified for metallic solids. We give some important, and essential, results for
the Debye theory. Further discussion of the Debye theory can be found in chapter
15. Just as in the Einstein theory, in Debye theory too there is a characteristic Debye
Temperature Θ
D
=(
6
π
)
1/3
T
E
.Thelow temperature behaviour of speci ...