Structures of Solids

(1)

11

SOLIDS

can be divided into

can be divided into two

two

catagories.



Crystalline



Amorphous

Crystalline has long range order

Amorphous materials have short range order

Effect of Crystallinity on Physical properties

(2)

22

Crystal

ype

P

Pa

ar

rt

ti

ic

cl

le

es

s

"orces

!

!n

nt

te

er

rp

pa

ar

rt

ti

ic

cl

le

e

P

Ph

hy

ys

si

ic

ca

al

l

#

#e

eh

ha

av

vi

io

ou

ur

r

E

Ex

xa

am

mp

pl

le

es

s

Atomic Atomic $olecular $olecular $etallic $etallic !onic !onic %etwor& %etwor& Atoms Atoms $olecules $olecules Atoms Atoms Positive and Positive and negative negative ions ions Atoms Atoms 'ispersion 'ispersion 'ispersion 'ispersion 'ipole-dipole 'ipole-dipole (-bonds (-bonds $etallic bond $etallic bond !on-ion !on-ion attraction attraction Covalent Covalent )) *oft*oft ) +ery low mp ) +ery low mp

) Poor thermal and electrical

conductors



 "airly soft "airly soft



 ,ow to ,ow to moderate mpmoderate mp



 Poor thermal and electrical Poor thermal and electrical

conductors



 *oft to hard *oft to hard



 ,ow to very high mp ,ow to very high mp



 $ellable and ductile $ellable and ductile



 Excellent thermal and Excellent thermal and electricaelectricall

conductors



 (ard and brittle (ard and brittle



 (igh mp (igh mp



 ood thermal and electrical ood thermal and electrical

conductors in molten condition

)) +ery hard+ery hard

) +ery high mp

conductors conductors roup A roup A %e to /n %e to /n 0 0₂₂ P P__ ( (₂₂00 *ucrose *ucrose

%a Cu "e

%aCl Ca"

%aCl Ca"₂₂

$g0

*i0

*i0₂₂34uart5634uart56

C 3'iamond6

7PE* 0" C/7A,,!%E 0,!'*

(3)

22

Crystal

ype

P

Pa

ar

rt

ti

ic

cl

le

es

s

"orces

!

!n

nt

te

er

rp

pa

ar

rt

ti

ic

cl

le

e

P

Ph

hy

ys

si

ic

ca

al

l

#

#e

eh

ha

av

vi

io

ou

ur

r

E

Ex

xa

am

mp

pl

le

es

s

Atomic Atomic $olecular $olecular $etallic $etallic !onic !onic %etwor& %etwor& Atoms Atoms $olecules $olecules Atoms Atoms Positive and Positive and negative negative ions ions Atoms Atoms 'ispersion 'ispersion 'ispersion 'ispersion 'ipole-dipole 'ipole-dipole (-bonds (-bonds $etallic bond $etallic bond !on-ion !on-ion attraction attraction Covalent Covalent )) *oft*oft ) +ery low mp ) +ery low mp

conductors



 "airly soft "airly soft



 ,ow to ,ow to moderate mpmoderate mp



 Poor thermal and electrical Poor thermal and electrical

conductors



 *oft to hard *oft to hard



 ,ow to very high mp ,ow to very high mp



 $ellable and ductile $ellable and ductile



 Excellent thermal and Excellent thermal and electricaelectricall

conductors



 (ard and brittle (ard and brittle



 (igh mp (igh mp



 ood thermal and electrical ood thermal and electrical

conductors in molten condition

)) +ery hard+ery hard

) +ery high mp

conductors conductors roup A roup A %e to /n %e to /n 0 0₂₂ P P__ ( (₂₂00 *ucrose *ucrose

%a Cu "e

%aCl Ca"

%aCl Ca"₂₂

$g0

*i0

*i0₂₂34uart5634uart56

C 3'iamond6

7PE* 0" C/7A,,!%E 0,!'*

(4)

88

Molecular Solids

Covalent Solids

Ionic solids

Metallic solids

Na Na++ Cl Cl-

-STRUCTURES OF CRYSTALLINE SOLID TYES

(5)



'!A$0%'

49A/:

/AP(!E

(6)

;;

CRYST

AL STRUCTUR

E

Cr!stal structure

is the

"eriodic arran#e$ent o% ato$s

in the

crystal. Association of each

lattice "oint

with a group of

atoms

3#asis or $otif6

.

Lattice

< !nfinite array of points in space in which each point has

identical surroundings to all others.

S"ace Lattice

≠≠

Arrangement

s of

atoms

=

,attice

of

points

onto

which

the

atoms

are

hung.

Elemental solids 3Argon6<

&asis

=

sin#le ato$'

Polyatomic Elements<

&asis

=

t(o or %our ato$s

..

Complex organic compounds<

&asis

t)ousands o% ato$s

+

*pace ,attice

+

#asis

*

Crystal *tructure

*

)

) )

) ))

)

) )

) ))

)

) )

) ))

(7)

>

ONE DIMENTIONAL LATTICE

ONE DIMENTIONAL UNIT CELL

a

UNIT CELL <

&uildin# loc, re"eats in a re#ular (a!

(8)

?

(9)



a

b

a

≠

b

θ ≠

@B

a

≠

b

θ

= @B

a

b

a = b

θ

= @B

a

≠

b

θ

= @B

a

b

a = b

θ

=12B

a

(10)

@

(11)

1

T.O DIMENTIONAL UNIT CELL OSSI&ILITIES OF NaCl

Na+

(12)

-11

T0REE DIMENTIONAL UNIT CELLS 1 UNIT CELL S0AES

2

3

4

5

6

7

8

(13)

12

Primitive 3



6 #ody Centered 3

I

6 "ace Centered 3

F

6 C-Centered 3

C

6 LATTICE TYES

(14)

18

&RA9AIS LATTICES

8 UNIT CELL TYES + 5 LATTICE TYES * 25 &RA9AIS LATTICES

(15)

1

COUNTIN: ATOMS IN T0E T0REE DIMENTIONAL UNIT CELL



9erte;<corner= ato$ s)ared !

> cells

2

1

_>

ato$ "er cell



Ed#e ato$ s)ared !

5 cells

2

1

₅

ato$ "er cell



Face ato$ s)ared !

3 cells

2

1

₃

ato$ "er cell



_{&od! uni?ue to}

_{2 cell}

₂

_{ato$ "er cell}

Atoms in different positions in a cell are shared by

differing numbers of unit cells

(16)

1;

(17)

1>

Close-pac&ing-

0E/A:ONAL

coordination of each sphere

SIN:LE LAYER AC@IN:

(18)

1?

(19)

1

(20)

(21)

2

(22)

21

85B S"ace is occu"ied'

Coordination nu$er * 23

+. 1 atom = 8D r

88

+. 9nit cell = a

8

= r

8

Efficiency of pac&ing = +.  atom < +. unit cell

= +.  atom < +. cubic

= ?;

C9#!C C,0*E PACE'

(EFA0%A,C,0*E PACE'

+. 1 atom = 8D r

88

+. 9nit cell = >.a.c = >.3r.rG86.c

Eff. 0f pac&.= +. > atom < +. hexagonal

= ?;

(23)

22

NON-CLOSE-AC@ED STRUCTURES

7>B o% s"ace is occu"ied

Coordination nu$er * >

63B o% s"ace is occu"ied

Coordination nu$er * 7

+. 1 atom = 8D r8

+. 9nit cell = a8 = r8

Eff. 0f pac&. = +. 2 atom < +. cubic

= >2

+. 1 atom = 8D r8

+. 9nit cell = a8 = r8

Eff. 0f pac&. = +. 1 atom < +. cubi

= ;28

Body centered cubic

(24)

28

' = mass per sel satuan  +olume sel satuan

= massa molar x : molar volum

= "H x :  3+ x %6

+= volume sel satuan

%= bilangan avogadro

:= Iumlah atom dalam sel satuan

' = 3 "H x : x1>>6 + 3



A6

gramcm

8

(25)

2

>

ABCABC…

12 Cubic close

pac&ed

ABABAB…

12 (exagonal

close pac&ed

ABABAB…



#ody-centered

Cubic

AAAAA…

Primitive

Cubic

*tac&ing

pattern

Coordination

number

*tructure

Non-close "ac,in# Close "ac,in#

(26)

2;

> 23

Coordination

nu$er 7

(27)

(28)

2?

ALLOTROES

E;istence o% sa$e ele$ent in di%%erent cr!stal

structures'

e#' Caron

(29)

2

TETRA0EDRAL 0OLES

OCTA0EDRAL 0OLES

TYE OF 0OLES IN CLOSE AC@IN:

(30)

2@

(31)

8

(32)

81

Ionic structures $a! e derived %ro$ t)e

occu"ation o% )oles ! o""ositel! c)ar#ed

ions <interstitial sites= in t)e close-"ac,ed

arran#e$ents o% ions'

(33)

82

/adius ratio

Coordinate

number

positive ions pac&

(oles in which

.22; J .1



etrahedral holes

.1 J .?82

>

0ctahedral holes

.?82 J 1



Cubic holes

0ole Occu"ation - RADIUS RATIO RULE

/adius of the positive ion

/adius ratio

=

(34)

88

IONIC CRYSTAL TYES

!onic crystal

type

Co-ordination

number

A

/

*tructure type

A/

₃

A/

₄

7

7 >

>

7

4 >

5

7

3 NaCl

CsCl

Rutile<TiO

₃

=

Fluorite <CaF

₃

=

ReO

₄

(35)

8

a

= ROC@ SALT STRUCTURE

<NaCl=

)

CC Cl-_{(it) Na}+_{in all Octa)edral} )oles

)

_Lattice FCC

)

Motif  Cl at <= Na at <2₁

3=

)

5 NaCl in one unit cell

)

Coordination 77 <octa)edral=

)

Cation and anion sites are to"olo#icall! identical

STRUCTURE TYE - A/

(36)

8;

)

CC S3-_{(it) n}3+_{in )al% Tetra)edral )oles < T+ Gor T-H} %illed=

)

_Lattice_{ FCC}

)

_{5 nS in one unit cell}

)

Motif  S at <= n at <2₁ 5 2₁ 5 2₁ 5=

)

_Coordination_{ 55 <tetra)edral=}

)

_{Cation and anion sites are to"olo#icall! identical}

(37)

8>

)

_{0C (it) Ni in all Octa)edral )oles}

)

Lattice 0e;a#onal - 

)

Motif  3Ni at <=  <2₁ 3= 3As at < 3₁ 4 2₁ 4 2₁ 5=  <2₁ 4 3₁ 4 4₁ 5=

)

_{3 NiAs in unit cell}

)

_Coordination_{ Ni 7 <octa)edral=  As 7 <tri#onal} "ris$atic=

(38)

8?

)

0C S3-_{(it) n}3+_{in )al% Tetra)edral )oles < T+ Gor T-H} %illed =

)

Lattice 0e;a#onal - 

)

Motif  3 S at <=  <3₁ 4 2₁ 4 2₁ 3= 3 n at < 3₁ 4 2₁ 4 2₁ >=  <6₁ >=

)

3 nS in unit cell

)

Coordination 55 <tetra)edral=

d= .URTITE < nS =

(39)

8

(40)

8@

STRUCTURE TYE - A/

NON J CLOSE AC@ED STRUCTURES

CU&IC- <RIMITI9E=

< e#' Cesium Chloride ( CsCl ) )

)

Motif  Cl at <= Cs at <

2

₁

3



2

₁

3



2

₁

3

=

)

_{2 CsCl in one unit cell}

)

_{Coordination >> <cuic=}

)

Ado"tion ! c)lorides ro$ides and iodides o% lar#er cations

)

e.g. Cs

+

_{ Tl}

+

_{ N0}

5

(41)



)

CC Ca3+_{(it) F}-_{in all Tetra)edral )oles}

)

Lattice %cc

)

Motif  Ca3+_{at <= 3F}-_{at <}2₁ 5 2₁ 5 2₁ 5=  < 4₁ 5 4₁ 5 4₁ 5=

) 5 CaF

₃ in one unit cell

)

Coordination Ca3+_{> <cuic=  F}-_{5 <tetra)edral=}

)

In t)e related Anti-Fluorite structure Cation and Anion "ositions are reversed

STRUCTURE TYE - A/

₃

(42)

1

)

_{CC Ca}3+_{(it) F}-_{in all Tetra)edral )oles}

)

Lattice %cc

)

Motif  Ca3+_{at <= 3F}-_{at <}2₁ 5 2₁ 5 2₁ 5=  < 4₁ 5 4₁ 5 4₁ 5=

) 5 CaF

₃ in one unit cell

)

Coordination Ca3+_{> <cuic=  F}-_{5 <tetra)edral=}

)

_{In t)e related Anti-Fluorite structure Cation and}

STRUCTURE TYE - A/

₃

(43)

2

ALTERNATE RERESENTATION OF FLUORITE

STRUCTURE

AntiJFlourite structure <or Na

₃

O structure= J "ositions o%

cations and anions are reversed related to Fluorite structure

(44)

8

RUTILE STRUCTURE TiO

₃

)

_{0C o% O}

3-

_{< distorted )c" or Tetra#onal=}

(45)



)

0C o% Iodide (it) Cd in Octa)edral )oles o% alternate la!ers

)

CC analo#ue o% CdI

₃

is CdCl

₃

STRUCTURE TYE - A/

₃

NON-

CLOSE AC@ED STRUCTURE

(46)

;

(47)

>

0C ANALO:UE OF FLOURITE <CaF

₃

= K

)

_{No structures o% 0C are ,no(n (it) all Tetra)edral sites <T+}

and T-= %illed' <i.e. t)ere is no 0C analo#ue o% t)e Fluorite1 Anti#

Fluorite Structure='

)

_{T)e T+ and T- interstitial sites aove and elo( a la!er o%}

close-"ac,ed s")eres in 0C are too close to eac) ot)er to tolerate t)e

coulo$ic re"ulsion #enerated ! %illin# (it) li,e-c)ar#ed s"ecies

.

Unknown HCP

analogue of

Fluorite

(48)

?

(49)



For$ula T!"e and %raction o% sites

occu"ied

CC

0C

A/

All octahedral

(alf tetrahedral 3K or -6

/oc& salt 3%aCl6

:inc #lend 3:n*6

%ic&el Arsenide 3%iAs6

Hurt5ite 3:n*6

A/₃

All etrahedral

(alf octahedral 3ordered

framewor&6

(alf octahedral 3Alternate

layers full empty6

"luorite 3Ca"

₂

6

Anti-"luorite 3%a

₂

06 Anatase 3i0

₂

6 Cadmium Chloride

3CdCl

₂

6 %ot &nown

/utile 3i0

₂

6 Cadmium iodide 3Cd!

₂

6

A₄/

All octahedral L All

etrahedral

,i

8

#i

%ot &nown

A/₄

0ne third octahedral

7Cl

₈

#i!

₈

(50)

@

Roc, salt<NaCl= J occu"ation o% all octa)edral )oles

)

9er! co$$on <in ionics covalents  inter$etallics =

)

_{Most al,ali )alides <CsCl Cs&r CsI e;ce"ted=}

)

Most o;ides 1 c)alco#enides o% al,aline eart)s

)

_{Man! nitrides carides )!drides <e'#' rN TiC Na0=}

Fluorite <CaF₃= J occu"ation o% all tetra)edral )oles

)

Fluorides o% lar#e divalent cations c)lorides o% Sr &a

)

O;ides o% lar#e ?uadrivalent cations <r 0% Ce T) U=

Anti#Fluorite <Na₃O= J occu"ation o% all tetra)edral )oles

)

_{O;ides 1c)alco#enides o% al,ali $etals}

$inc Blende%&'halerite < nS = J occu"ation o% )al% tetra)edral )oles

)

_{For$ed %ro$ olariin# Cations <Cu}+_{ A#}+_{ Cd}3+_{ :a}4+_{'''= and} olariale Anions <I-_{ S}3-_{ }4-_{ '''=}

e.g. Cu<FCl&rI= A#I n<SSeTe= :a<As= 0#<SSeTe=

(51)

;

E;a$"les o%

0C

Structure Ado"tion

Nic,el Arsenide < NiAs = J occu"ation o% all octa)edral )oles

)

Transition $etals (it) c)alco#ens As S &i e.g. Ti<SSeTe= Cr<SSeTeS= Ni<SSeTeAsSSn=

Cad$iu$ Iodide < CdI₃= J occu"ation )al% octa)edral <alternate= )oles

)

Iodides o% $oderatel! "olarisin# cations ro$ides and c)lorides o% stron#l! "olarisin# cations' e.g. I₃ Fe&r₃ 9Cl₃

) 0!dro;ides o% $an! divalent cations'

e.g. <M#Ni=<O0=₃

) Di-c)alco#enides o% $an! ?uadrivalent cations '

e.g. TiS₃ rSe₃ CoTe₃ Cad$iu$ C)loride CdCl₃ <CC eui*alent of CdI₃= J )al% octa)edral )oles

) C)lorides o% $oderatel! "olarisin# cations

e.g. M#Cl₃ MnCl₃

) Di-sul%ides o% ?uadrivalent cations

e.g. TaS₃ NS₃ <CdI₃ %or$ as (ell=

) Cs

₃O )as t)e anti -cad$iu$ c)loride structure

(52)

;1

ERO9S@ITE STRUCTURE



For$ula unit J A&O

₄



CC o% A ato$s<i##er= at t)e corners



O ato$s at t)e %ace centers

(53)

;2

)

_Lattice_{ ri$itive Cuic <idealised structure=}

) 2 CaTiO

₄ "er unit cell

)

A#Cell Motif  Ti at <  = Ca at <2₁ 3 2₁ 3 2₁ 3= 4O at <2₁ 3  = < 2₁ 3 = <  2₁ 3=

)

Ca 23-coordinate ! O <cuocta)edral=

)

_{Ti 7-coordinate ! O <octa)edral=}

)

O distorted octa)edral <5;Ca + 3;Ti=

ERO9S@ITE

) Examples< %a%b0

₈

 #ai0

₈



Ca:r0

₈

 7Al0

₈

 $g"

₈

Structures of Solids

SOLIDS

SOLIDS

can be divided into

can be divided into two

two

catagories.

catagories.

Crystalline

Crystalline

Amorphous

Amorphous

Crystalline has long range order

Crystalline has long range order

Amorphous materials have short range order

Amorphous materials have short range order

Effect of Crystallinity on Physical properties

Crystal

Crystal

ype

ype

P

Pa

ar

rt

ti

ic

cl

le

es

s

"orces

"orces

!

!n

nt

te

er

rp

pa

ar

rt

ti

ic

cl

le

e

P

Ph

hy

ys

si

ic

ca

al

l

#

#e

eh

ha

av

vi

io

ou

ur

r

E

Ex

xa

am

mp

pl

le

es

s

7PE* 0" C/7*A,,!%E *0,!'*

Crystal

Crystal

ype

ype

7PE* 0" C/7A,,!%E 0,!'*

7PE* 0" C/7A,,!%E 0,!'*