Welcome to 3.091Lecture 33

December 4, 2009

Unary Phase Diagrams

snowflake obsidian: black glassy phase + white xtalline phaseSiO2 - MgO - Fe3O4

Courtesy of WoofBC on Flickr.

WATER

Normal melting point

Supercriticalfluid

Criticalpoint

LiquidSolid

Gas

Normalboilingpoint

Triple point (Tt)6.0 x 10-3

1

217.7Pr

essu

re (a

tm)

Temperature (oC)

0 0.0098 100 374.4

Phase Diagram of Water

Image by MIT OpenCourseWare.

00

10

20 ct(4)

liquidfcc(8)

(diamond)

Silicon

P (G

Pa)

1000T (K)

2000

Image by MIT OpenCourseWare.

P (G

Pa)

0

2

4

6

Aluminum

fcc

liquid

T (K)0 400 800 1200

Image by MIT OpenCourseWare.

WATER

WATER

Professor Sadoway’s lab coat is from MAISON DUTECH:

it’s French!

m.p. b.p. (K) (K)

oxygen 55 90

argon 84 87

nitrogen 63 77

polymorphs:different atomicarrangements at constant composition

1 atm = 101325 Pa = 0.1 MPa = 14.7 psi = 1 bar 1 GPa = 10,000 atm

P (G

Pa)

0

5

10

15

20

T (K)

0 200 400 600 800

st(2)(γ)

hcp (β)

sc(4) (α)

liquid

sc(8) (δ)

Nitrogen

η

ζ

rh(8) (ε)

Image by MIT OpenCourseWare.

Gas

Liquid

Supercriticalfluid

Solid

Temperature (oC)

Pres

sure

(atm

)

73.0

5.11

1

-78.5 -56.4 31.1

Carbon dioxide (CO2)

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. Reprintedwith 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 CreativeCommons license. For more information,see http://ocw.mit.edu/fairuse.Source: Schulte, O., and W. B. Holzapfel. "Phase Diagram for Mercury up to 67 GPaand 500 K." Phys Rev B 48 (1993); 14009-14012.

Calder – Miró Mercury Fountainin honor of the miners of AlmadenMiro Museum, Barcelona, Spain

2.5

5.0

7.5

P (G

Pa)

10.0

12.5

0

T (K)

0 200 400 600 800

II'cm(4)

(II)

liquid

tet(8)(VII)

rh(2)(I)

orth(8)(III)

IV

V

VIII bcc (VI)

IX

Bismuth

Image by MIT OpenCourseWare.

A

B

C

EDVI

VIII

IV

00

2

4

6

200

fco(16) (I)sm(6) (II)

400T (K)

600 800

III

V

VIIIX

X

XI

XIIP

(GPa

)

Sulfur

liquid

Image by MIT OpenCourseWare.

allotropes of sulfur

allotropes: forms of an element differing in bonding and molecular structure,e.g., O2 and O3 are allotropes of oxygen

S S2

S6 S8

Sn (n = 2000 - 5000)

Image by MIT OpenCourseWare.

polymorphs of sulfur

rhombic monoclinic

α = β at 95.5ºC

Image sources: Left, public domain. Right, courtesy of fluor_dooublet on Flickr.

β = λ at 119ºC

λ = µ at 160ºCforming “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)

ice VII100°C

25 kbar

Courtesy of Dover Publications. Used with permission.

WATER

MIT OpenCourseWarehttp://ocw.mit.edu

3.091SC Introduction to Solid State ChemistryFall 2009

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