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Chem 104A, UC, Berkeley
Solid State Structure
Reading:
MT Chapter 7DG Chapter 7
Chem 104A, UC, Berkeley
2
Chem 104A, UC, Berkeley
MgB2, superconductor, Tc=39 K
Chem 104A, UC, Berkeley
CaB6
3
Chem 104A, UC, BerkeleySand Silicon Computer Chips
Chem 104A, UC, Berkeley
Gemstone
Sapphire
GarnetTopaz
Synthetic ZrO2
The general formula X3Y2(SiO4)3Al2SiO4(F,H)2
O
4
Chem 104A, UC, Berkeley
ZrO2 Diamond
Chem 104A, UC, Berkeley
Abalone Shell
5
Chem 104A, UC, Berkeley
Source: National Mineral CollectionSmithsonian National Museum
CuPb(AsO4)(OH)
Chem 104A, UC, Berkeley
Source: National Mineral CollectionSmithsonian National Museum
6
Chem 104A, UC, Berkeley
Chem 104A, UC, Berkeley
7
Chem 104A, UC, Berkeley
Chem 104A, UC, Berkeley
8
Chem 104A, UC, Berkeley
Fluorite with quartz
Chem 104A, UC, Berkeley
9
Chem 104A, UC, Berkeley
diamond crystal in kimberlite
Chem 104A, UC, Berkeley
10
Chem 104A, UC, Berkeley
Crystalline Solids
Chem 104A, UC, BerkeleyCARBON : Diamond
11
Chem 104A, UC, Berkeley
Amorphous Solids
Chem 104A, UC, Berkeley
Molecular solids Covalent
Ionic Metallic
12
Chem 104A, UC, Berkeley
Chem 104A, UC, Berkeley
Na+Cl-
IE(Na)= 5.14eV
EA(Cl) =3.61 eV ?? Why NaCl solid
13
Chem 104A, UC, Berkeley
E
U0
r
nrc r
B
r
eZZEEU
0
2
4
Ionic Pair
0 Permittivity of vacuum
Chem 104A, UC, Berkeley
Ion Conf. n
He 5
Ne 7
Ar, Cu+ 9
Kr, Ag+ 10
Xe, Au+ 12
Born Exponent
14
Chem 104A, UC, Berkeley
1
111 1
1
22
22
2
2 2
2
22
22
3
33
3
33
33
Chem 104A, UC, Berkeley
Lattice Stabilization Energy:Ions adopt a simple lattice structure that maximize favorable Electrostatic interactions.
......)5
24
4
6
3
8
2
126(
4 0
2
eZZ
E latticec
......5
24
4
6
3
8
2
126 NaClA
74756.1
15
Chem 104A, UC, Berkeley
Structure Type Madelung ConstantCsCl 1.763NaCl 1.748
ZnS (Wurtzite) 1.641ZnS (Zinc Blende) 1.638
M& T: p227
Chem 104A, UC, BerkeleyFor one mole of a crystalline compound:
Lattice energy =nrc r
NB
r
eZNZAEEU
0
2
4N: Avogadvo’s constant, 6.02e23E
U0
r
16
Chem 104A, UC, Berkeley
Energy is Minimum when 0dr
dU
n
reZAZB
r
nNB
r
eZNZA
n
n
0
12
120
2
4
04
)1
1(4 00
2
0 nr
eZANZU
Born-Lande Equation:
Chem 104A, UC, Berkeley
1
111 1
1
22
22
2
2 2
2
22
22
3
33
3
33
33
o
Ar 81.20 n=8 U0=-760kJ/mol
17
Chem 104A, UC, Berkeley
Born-Haber Cycle:
M(g) M+ (g)
+X(g) X-(g)
M(s) + ½ X2 (g) MX (s)
IEH
EAH
AXHAMH
fH
0UHHHHH EAIEAXAMf
0U
Chem 104A, UC, Berkeley
For NaCl:
109kJ/mol
IE 493.7kJ/mol
1/2121kJ/mol
EA -356kJ/mol
U -764.4kJ/mol
fH =-396.7kJ/mol
Experimentally:
-410.9kJ/mol
AMH
AXH
18
Chem 104A, UC, Berkeley
Ucalc. UBorn-Haber
AgF 920 953 33
AgCl 832 903 71
AgBr 815 895 80
AgI 777 882 105
U
Increasing covalent!
Chem 104A, UC, Berkeley
MgO 3938 kJ/mol
LiF 1024 NaF 911
CaO 3566 LiCl 861 KF 815
SrO 3369 LiBr 803 RbF 777
BaO 3202 LiI 744 CsF 748
Some Lattice Energies:
Melting point: MgO: 2800 CCaO: 2572 CBaO: 1923 C
19
Chem 104A, UC, Berkeley
X-Ray Spectroscopy
/hchE
35KeV ~ 0.1-1.4ACu K 1.54 A
Mo:
X-Ray Diffraction
Chem 104A, UC, BerkeleyX-Ray Diffraction
20
Chem 104A, UC, Berkeley
(200)
Powder diffraction
X-Ray
Chem 208 (X-ray Crystallography) - Raymond
Chem 104A, UC, Berkeley
21
Chem 104A, UC, BerkeleyPowder diffraction
Chem 104A, UC, Berkeley
ZrO2 Diamond