Welcome to 3.091
Lecture 33
December 4, 2009
Unary Phase Diagrams
Courtesy of WoofBC on Flickr.
snowflake obsidian:
black glassy phase + white xtalline phase
SiO2 - MgO - Fe3O4
WATER
Phase Diagram of Water
Supercritical
fluid
217.7
Pressure (atm)
Critical
point
Normal melting point
Solid
Liquid
1
Normal
boiling
point
6.0 x 10-3
Gas
Triple point (Tt)
0 0.0098
100
374.4
Temperature (oC)
Image by MIT OpenCourseWare.
Silicon
20
P (GPa)
ct(4)
10
0
fcc(8)
(diamond)
0
1000
T (K)
liquid
2000
Image by MIT OpenCourseWare.
Aluminum
P (GPa)
6
4
fcc
2
liquid
0
0
400
800
1200
T (K)
Image by MIT OpenCourseWare.
WATER
WATER
Professor Sadoway’s lab coat
is from MAISON DUTECH:
it’s French!
m.p.
(K)
b.p.
(K)
oxygen
55
90
argon
84
87
nitrogen 63
77
Nitrogen
ζ
20
polymorphs:
different atomic
arrangements
at constant
composition
η
P (GPa)
15
rh(8) (ε)
sc(8) (δ)
10
st(2)
(γ)
5
liquid
hcp (β)
0
sc(4) (α)
0
200
400
600
800
T (K)
Image by MIT OpenCourseWare.
1 atm = 101325 Pa = 0.1 MPa = 14.7 psi = 1 bar
 1 GPa = 10,000 atm
Supercritical
fluid
Carbon dioxide (CO2)
Pressure (atm)
73.0
Liquid
Solid
Gas
5.11
1
-78.5
-56.4
31.1
Temperature (oC)
Image by MIT OpenCourseWare.
ZIRCONIA (ZrO2)
Source: Bergeron, C., and S. Risbud, Introduction to Phase Equilibria in Ceramics. American Ceramic Society, 1984.
Reprinted with permission of The American Ceramic Society, www.ceramics.org. Some rights reserved.
CARBON
Source: Bergeron, C., and S. Risbud,
Introduction to Phase Equilibria in Ceramics.
American Ceramic Society, 1984. Reprinted
with permission of The American Ceramic
Society, www.ceramics.org.
Some rights reserved.
MERCURY
© American Physical Society. All rights reserved. This content is excluded from our Creative Commons license. For more information, see http://ocw.mit.edu/fairuse.
Source: Schulte, O., and W. B. Holzapfel. "Phase diagram for mercury up to 67 GPa and 500 K." Phys Rev B 48 (1993); 14009-14012.
MERCURY
© American Physical Society. All rights reserved.
This content is excluded from our Creative
Commons license. For more information,
see http://ocw.mit.edu/fairuse.
Source: Schulte, O., and W. B. Holzapfel.
"Phase Diagram for Mercury up to 67 GPa
and 500 K." Phys Rev B 48 (1993); 14009-14012.
Calder – Miró
Mercury Fountain
in honor of the miners of Almaden
Miro Museum, Barcelona, Spain
Bismuth
12.5
IX
P (GPa)
10.0
VIII
bcc (VI)
7.5
V
5.0
tet(8)
(VII)
IV
orth(8)
(III)
2.5
0
rh(2)
(I)
0
200
liquid
cm(4)
(II)
400
II'
600
800
T (K)
Image by MIT OpenCourseWare.
Sulfur
6
P (GPa)
XII
4
X
2
IX
VII
XI
VIII
V
D
VI
fco(16) (I)
0 sm(6) (II)
0
200
III
IV
liquid
E
B
C
A
400
T (K)
600
800
Image by MIT OpenCourseWare.
allotropes of sulfur
S
S2
S8
S6
Sn (n = 2000 - 5000)
Image by MIT OpenCourseWare.
allotropes: forms of an element
differing in bonding and molecular structure,
e.g., O2 and O3 are allotropes of oxygen
polymorphs of sulfur
α = β at 95.5ºC
rhombic
monoclinic
Image sources: Left, public domain. Right, courtesy of fluor_dooublet on Flickr.
β = λ at 119ºC
λ = µ at 160ºC
forming “plastic” sulfur,
i.e., amorphous
© source unknown. All rights reserved. This content is excluded from our Creative
Commons license. For more information, see http://ocw.mit.edu/fairuse.
WATER (H2O)

Courtesy of Dover Publications. Used with permission.

ice VII
100°C
25 kbar
WATER
MIT OpenCourseWare
http://ocw.mit.edu
3.091SC Introduction to Solid State Chemistry
Fall 2009
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