Solids: Heat Capacities Flashcards
1
Q
What type of motion can a solid have
A
Vibrational motion (small)
2
Q
Vibrational motion energy (quantised)
A
En = (n+1/2)ℏw, change in energy compared to n=0 will be Delta E = nℏw
3
Q
What can we do with this energy change to describe total energy
A
Sub delta E in to Boltzmann partition
4
Q
U total energy =
A
Sum NiEi between 0 and infinty = (Nℏw)/(e^(ℏw/kt) -1)
5
Q
Heat capacity at constant volume =
A
dU/dT at constant V so we differentiate our value for U with respect to T.
6
Q
Activation temperature for solid vibrations
A
θ_E = hv_E/T
v_E is vibrational frequency
7
Q
θ_E subbed into C_V equation for
A
ℏw/k
