材料科学基础
Fundamental of Materials
Prof,Tian Min Bo
Tel,62795426, 62772851
E-mail,tmb@mail.tsinghua.edu.cn
Department of Material Science and Engineering
Tsinghua University,Beijing 100084
Lesson eleven
§ 3.10 Silicates
? Ⅰ.Introduction
Silicates are compounds that mainly
composed of [SiO4],It is the essential
components of most rock and soil,such as
quartz,feldspar,mica etc.
? Ⅱ.Features
1,Basic sell,[SiO4]
rsi/rO＝ 0.40/1.35＝ 0.30<0.414
[SiO4]4-
4－
SiO4 tetrahedron
Si4+ is the cation that have small radii and large
electrovalence.
The distance between Si and O:
Si－ O, 1.6 ?(practical) < 1.75 ? (theoretic)
(0.40+1.35)
2,The bonds of Si-O-Si is not beeline but zigzag
line,
The angle of oxygen point is 145o in silicate.
3,For every oxygen,there is at most two SiO4
tetrahedrons can share it,
4,The SiO4 tetrahedrons can exist isolated or
connect each other at common point.
5,In silicate structure:
So,the CN of aluminum could be 4 or 6
6,The chemic expression or mineral.
molecular formula, Al2O3·2SiO2·H 2O ; ZrO2·SiO2
structural formula, Al2[Si2O5](OH)4 ; Zr[SiO4]
aluminum
+ oxygen
aluminum-oxygen
tetrahedrons
replace SiO4
tetrahedrons aluminum-silicate
aluminum-oxygen octahedron
? Ⅲ.Classification
island
chain (single,double)
sheet (single,double)
frame
1,Island silicates
Si:O=1:4 Si:O=1:3.5 Si:O=1:3
Si:O=1:3 Si:O=1:3
? characteristic
single:
? molecular formula,
M4+[SiO4],M22+[SiO4]
? typical minerals
olivine,zircon,garnet
[SiO4]四面体及其硅氧团之间不共顶点相连，
硅氧团被金属离子隔开形成孤立的岛状。
硅氧四面体还可以成对硅氧团出现，或成三
方环状、四方环状或六方环状硅氧团出现，这些
有限的硅氧团之间被金属阳离子隔开
双环
三环
四环
六环
2,Chain silicates
single
? characteristic
硅氧四面体通过共用两个或者两个以上的顶点，连接形成
一向延长的链状结构。链与链之间被金属阳离子隔开。
single
Si:O=1:3
? typical minerals
pyroxenes,CaMg[Si2O6],Mg2[Si2O6]
double
? typical minerals
tremolite ; (OH)6Mg6(Si4O11)·H2O
double
Si:O=4:11
3,Sheet silicates
Si:O=4:10
? characteristic
[SiO4]以三个以上的顶角相连形成在二维方向呈六角对称
的平面无限延伸的层状结构。
? typical minerals
talc
Mg3[(OH)2Si4O10]
muscovite
KAl2[(OH)2AlSi3O10]
Kaolinite
Al2[(OH)4Si2O6]
4,Frame silicates
Si:O=1:2
cristobalite
? typical minerals
cristobalite（ silica SiO2）,feldspar
? characteristic
[SiO4]以其四个顶点在三维方向相连形成无限延伸的三维网络
结构。
§ 3.11 Summary
Types Features Structures Si:O Examples
1 Island
[SiO4]四面体及其
硅氧团之间不共顶点
相连，而是通过其余
金属离子相连，硅氧
团被金属离子隔开形
成孤立的岛状。
1:4 锆英石
镁橄榄石
石榴石
钇铝石榴石
硅氧四面体还可
以成对硅氧团出现，
或成三方环状、四方
环状或六方环状硅氧
团出现，这些有限的
硅氧团之间被金属阳
离子隔开
1:3.5
1:3
1:3
1:3
?4
?44]SiO[
?4
?6172 ]OSi[
?693 ]OSi[
?8124 ]OSi[
?12186 ]OSi[
][ 4SiOZr
]SiO[Mg 42
343223 ]S iO[RR ??
343223 ]S iO[AlY ??
Types Features Structures Si:O Examples
2 Chain
硅氧四面体通过
共用两个或者两个以
上的顶点，连接形成
一向延长的链状结构。
链与链之间被金属阳
离子隔开。
1:3
4:11
辉石
角内石
3 Sheet
[SiO4]以三个以上
的顶角相连形成在二
维方向呈六角对称的
平面无限延伸的层状
结构。
4:10
高岭石
云母
4 Frame
[SiO4]以其四个顶
点在三维方向相连形
成无限延伸的三维网
络结构。
1:2
石英
长石
沸石
?23]SiO[
?6114 ]OSi[
]OSi[R 622
? ? 2211452 OH]OSi[MgCa
?4104 ]OSi[
2SiO
? Ⅰ.Terminology:
components,composition and its description,
phase,structure
? Ⅱ.Classification:
solid solution
compounds
(intermediate phase)
substitutional ~
interstitial ~
primary ~ or terminal ~ ( it
must be disordered )
intermediate ~ or secondary ~ ordered ~disordered ~
normal valence ~
electron ~
size ~
ionic ~,Pauling's rule
disordered ~,(8-N) rule
interstitial ~
topological ~
simple ~
complex ~
laves phases
δ phasessilicates
island
chain
sheet
frame
amorphous
glass
metal glass
glass ceramics
ceramic glass
59.0?
A
Brr
59.0?
A
Brr
? Ⅲ.Features
Examples and Discussions
Exercise
Thank you !
11
Fundamental of Materials
Prof,Tian Min Bo
Tel,62795426, 62772851
E-mail,tmb@mail.tsinghua.edu.cn
Department of Material Science and Engineering
Tsinghua University,Beijing 100084
Lesson eleven
§ 3.10 Silicates
? Ⅰ.Introduction
Silicates are compounds that mainly
composed of [SiO4],It is the essential
components of most rock and soil,such as
quartz,feldspar,mica etc.
? Ⅱ.Features
1,Basic sell,[SiO4]
rsi/rO＝ 0.40/1.35＝ 0.30<0.414
[SiO4]4-
4－
SiO4 tetrahedron
Si4+ is the cation that have small radii and large
electrovalence.
The distance between Si and O:
Si－ O, 1.6 ?(practical) < 1.75 ? (theoretic)
(0.40+1.35)
2,The bonds of Si-O-Si is not beeline but zigzag
line,
The angle of oxygen point is 145o in silicate.
3,For every oxygen,there is at most two SiO4
tetrahedrons can share it,
4,The SiO4 tetrahedrons can exist isolated or
connect each other at common point.
5,In silicate structure:
So,the CN of aluminum could be 4 or 6
6,The chemic expression or mineral.
molecular formula, Al2O3·2SiO2·H 2O ; ZrO2·SiO2
structural formula, Al2[Si2O5](OH)4 ; Zr[SiO4]
aluminum
+ oxygen
aluminum-oxygen
tetrahedrons
replace SiO4
tetrahedrons aluminum-silicate
aluminum-oxygen octahedron
? Ⅲ.Classification
island
chain (single,double)
sheet (single,double)
frame
1,Island silicates
Si:O=1:4 Si:O=1:3.5 Si:O=1:3
Si:O=1:3 Si:O=1:3
? characteristic
single:
? molecular formula,
M4+[SiO4],M22+[SiO4]
? typical minerals
olivine,zircon,garnet
[SiO4]四面体及其硅氧团之间不共顶点相连，
硅氧团被金属离子隔开形成孤立的岛状。
硅氧四面体还可以成对硅氧团出现，或成三
方环状、四方环状或六方环状硅氧团出现，这些
有限的硅氧团之间被金属阳离子隔开
双环
三环
四环
六环
2,Chain silicates
single
? characteristic
硅氧四面体通过共用两个或者两个以上的顶点，连接形成
一向延长的链状结构。链与链之间被金属阳离子隔开。
single
Si:O=1:3
? typical minerals
pyroxenes,CaMg[Si2O6],Mg2[Si2O6]
double
? typical minerals
tremolite ; (OH)6Mg6(Si4O11)·H2O
double
Si:O=4:11
3,Sheet silicates
Si:O=4:10
? characteristic
[SiO4]以三个以上的顶角相连形成在二维方向呈六角对称
的平面无限延伸的层状结构。
? typical minerals
talc
Mg3[(OH)2Si4O10]
muscovite
KAl2[(OH)2AlSi3O10]
Kaolinite
Al2[(OH)4Si2O6]
4,Frame silicates
Si:O=1:2
cristobalite
? typical minerals
cristobalite（ silica SiO2）,feldspar
? characteristic
[SiO4]以其四个顶点在三维方向相连形成无限延伸的三维网络
结构。
§ 3.11 Summary
Types Features Structures Si:O Examples
1 Island
[SiO4]四面体及其
硅氧团之间不共顶点
相连，而是通过其余
金属离子相连，硅氧
团被金属离子隔开形
成孤立的岛状。
1:4 锆英石
镁橄榄石
石榴石
钇铝石榴石
硅氧四面体还可
以成对硅氧团出现，
或成三方环状、四方
环状或六方环状硅氧
团出现，这些有限的
硅氧团之间被金属阳
离子隔开
1:3.5
1:3
1:3
1:3
?4
?44]SiO[
?4
?6172 ]OSi[
?693 ]OSi[
?8124 ]OSi[
?12186 ]OSi[
][ 4SiOZr
]SiO[Mg 42
343223 ]S iO[RR ??
343223 ]S iO[AlY ??
Types Features Structures Si:O Examples
2 Chain
硅氧四面体通过
共用两个或者两个以
上的顶点，连接形成
一向延长的链状结构。
链与链之间被金属阳
离子隔开。
1:3
4:11
辉石
角内石
3 Sheet
[SiO4]以三个以上
的顶角相连形成在二
维方向呈六角对称的
平面无限延伸的层状
结构。
4:10
高岭石
云母
4 Frame
[SiO4]以其四个顶
点在三维方向相连形
成无限延伸的三维网
络结构。
1:2
石英
长石
沸石
?23]SiO[
?6114 ]OSi[
]OSi[R 622
? ? 2211452 OH]OSi[MgCa
?4104 ]OSi[
2SiO
? Ⅰ.Terminology:
components,composition and its description,
phase,structure
? Ⅱ.Classification:
solid solution
compounds
(intermediate phase)
substitutional ~
interstitial ~
primary ~ or terminal ~ ( it
must be disordered )
intermediate ~ or secondary ~ ordered ~disordered ~
normal valence ~
electron ~
size ~
ionic ~,Pauling's rule
disordered ~,(8-N) rule
interstitial ~
topological ~
simple ~
complex ~
laves phases
δ phasessilicates
island
chain
sheet
frame
amorphous
glass
metal glass
glass ceramics
ceramic glass
59.0?
A
Brr
59.0?
A
Brr
? Ⅲ.Features
Examples and Discussions
Exercise
Thank you !
11
