固体物理学课件：lecture2

(0, 1 , 1) 22
(1 ,0, 1) 22
Cl- (1 , 1 , 1) 222
(1 ,0,0) 2
(0,0, 1) 2
(0,0, 1) 2
b.
TlCl
CsCl structure
1 Cs+ 1 Cl-,
Cs+ (0,0,0)
Cl- (1 , 1 , 1) 222
c.
Si Ge
2C
d.
a1 = ai
a2
=
a 2
i
+
3a 2
j
a3 = ck
c/a =
8 3
a
•Example
•
sc
•
fcc
•
bcc
•Li Na K Rb Cs Fe
:
、
、
(
!)
1
x
x
x
1
2
3
4
原胞
a
a
R = na (n整数) Γ(x) = Γ(na + x)
2
b
a
a
原胞
aBiblioteka Baidu
原胞
a
a
R = na (n整数)
If
:
(n1, n2 , n3 整数)
R = n1a1 + n2a2 + n3a3
(n1, n2 , n3 整数)
1
sc
a1 = ai a2 = aj a3 = ak
2
bcc (Li, Na, K, Fe) a1
k j
o
a1
=
a (−i 2
+
j
+k)
a2
=
a (i 2
−
j
+
k)
a3
=
a (i 2
+
j
−k)
(1 , 1 ,0) OII 22
(0, 1 , 1) 22
OIII
(1 ,0, 1) 22
h. C60
C60
C60
i
V = 1 a3 2
a2 a3
3
fcc (Cu, Au, Ag, Al)
k j
a1 a2
a1
=
a 2
(
j
+
k
)
a2
=
a (i 2
+
k)
a3 i
V = 1 a3 4
a3
=
a (i 2
+
j)
NaCl ?
5.
a.
NaCl structure
4 Na+ 4 Cl-,
Na+ (0,0,0)
(1 , 1 ,0) 22
ZnS, GaAs
ZnS structure
1 Zn 1 S
e.
CaF2, BaF2 SrF2
CaF2 structure
1 Ca 2 F
f.
TiO2 SnO2 MnO2
structure
1 Ti 2 O
g.
CaTiO3 BaTiO3
Ca (1 , 1 , 1) Ti (0,0,0) 222
OI
b
a a
原胞
a
a
Be careful!
原胞
a
3
a
a
R = n1a1 + n2a2
W-S ?
(n1, n2整数)
a
b
WS
4
。 : :
a1, a2, a3或a,b,c以及α, β ,γ
Γ(r ) = Γ(r + l1a1 + l2a2 + l3a3) (l1,l2 ,l3 整数)
Γ(r ) = Γ(r + n1a + n2b + n3c)
( 1. 2.
): W—S
b=2a ,
3
1.1 1.2
、
(coordination number)
—
。
—
Z
sc: 6 fcc:12 bcc: 8
、
Si and Ge Cu and Ag
——
•Example
(hexagonal close-packed) :
hcp
Bravais lattice