(a) Ordered
(b) Disordered
Ordering in metal alloys. Two different atom types are interspersed: (a) ordered at low temperature, and
(b) disordered at high temperature.
Figure by MIT OCW.

1000
800
600
400
200
0
(a) Ordered
10 20
2000
α + L
1800
β + L
α + β
β
β + γ a + β '
β '
β ' + γ
γ
30 40 50 60
Composition (wt% Zn)
The copper-zinc phase diagram.
70
1600
γ + L
δ + ε
δ
δ + L
(b) Disordered
γ + ε
1400
1200
ε
ε + L
ε + η
η + L
1000
η
800
600
80 90 100
400
Figure by MIT OCW.
N1 H4
C2
H1
H2 H5
H3
H7
F1
F21
C3
H6
H4
B
N2
F22 H3
F21
H7
N2
C1
H2
H1
N1
C2
C3 F21
F21
F22
C1
C2
3
E
0
1
3
E
2
4
3
E
1
2
3
E
3
3
1
E
4
3 2
E
5
3 b a
Projection of the low-temperature structure of (CH
3
) phase, the orientations of the BF by successive 90 0
4
4
NBF
4
on the ab plane. In the high-temperature
groups are randomly distributed among the four orientations obtained
rotations around the B-F axis perpendicular to the drawing.
Figure by MIT OCW.

26
22
18
140 150
T(K)
160 170
Experimental heat-capacity points from the step measurements and from the thermograms in the transition region.
Figure by MIT OCW.
160
120
A
120
80
B 80
40
0
0 10 20 30 40 60 80
40
0
The temperature dependence of the molar heat capacity for two individual DNP monomer single crystals. The full curve shows a Debye fit.
Figure by MIT OCW.

Spheres (BCC)
60
χ N
40
Cylinders (HEX)
BCC
80
HEX
20
0
0 0.2
LAM
GYR
Disordered
0.4
0.6
fA
Gyroid (GYR)
BCC
HEX
0.8
1
Figure by MIT OCW.
Lamellar (LAM)

Images removed due to copyright reasons.

Model for a 3-atom solid as 1D harmonic oscillators
Energy
6
5
4 n
7
3
2
1
0
DE = (9/2)hv - (7/2) hv = hv
Microstate
Figure by MIT OCW.