Applications of Raman spectroscopy to the study of ...

41
Olivier Beyssac & Michele Lazzeri CNRS IMPMC Paris (olivier.beyssac or michele.lazzeri @impmc.upmc.fr) Applications of Raman spectroscopy to the study of graphitic carbons in the Earth sciences The Raman spectrum of graphitic carbons: Theory Characterizing graphitic carbons by Raman spectroscopy: Methodology

Transcript of Applications of Raman spectroscopy to the study of ...

Page 1: Applications of Raman spectroscopy to the study of ...

Oli

vie

r B

ey

ssa

c &

Mic

he

le L

azz

eri

CN

RS

IM

PM

C P

ari

s

(oli

vie

r.b

eys

sac

or

mic

he

le.l

azz

eri

@im

pm

c.u

pm

c.fr

)

Ap

pli

cati

on

s o

f R

am

an

sp

ect

rosc

op

y t

o t

he

stu

dy

of

gra

ph

itic

ca

rbo

ns

in t

he

Ea

rth

sci

en

ces

Th

e R

am

an

sp

ect

rum

of

gra

ph

itic

ca

rbo

ns:

Th

eo

ry

Ch

ara

cte

rizi

ng

gra

ph

itic

ca

rbo

ns

by

Ra

ma

n s

pe

ctro

sco

py

: M

eth

od

olo

gy

Page 2: Applications of Raman spectroscopy to the study of ...

1.

Intr

od

uct

ion

2.

Th

e R

am

an

sp

ect

rum

of

gra

ph

itic

ca

rbo

ns:

Th

eo

ry

2

.1.

Wh

y a

re t

he

D a

nd

2D

pe

aks

so

`u

niq

ue

'?

2

.2.

Ba

sic

con

cep

ts o

f q

ua

ntu

m m

ech

an

ics

an

d p

ert

urb

ati

on

th

eo

ry

2

.3.

Ele

ctro

nic

ga

p a

nd

re

son

an

t R

am

an

2

.4.

Fo

urt

h-o

rde

r p

ert

urb

ati

on

an

d d

ou

ble

re

son

an

t R

am

an

2

.5.

Ele

ctro

nic

str

uct

ure

an

d p

ho

no

n d

isp

ers

ion

in

gra

ph

en

e/g

rap

hit

e

2

.6.

Do

ub

le r

eso

na

nce

in

gra

ph

ite

2

.7.

Att

rib

uti

on

of

the

Ra

ma

n p

ea

ks

2

.8.

Sh

ap

e a

nd

wid

th o

f th

e 2

D p

ea

k

2

.9.

Inte

nsi

ty o

f th

e D

pe

ak

an

d t

he

Tu

inst

ra-K

oe

nig

re

lati

on

3.

Me

tho

do

log

y:

cha

ract

eri

zin

g g

rap

hit

ic c

arb

on

s b

y R

am

an

mic

rosp

ect

rosc

op

y

3

.1.

Ra

ma

n s

pe

ctro

sco

py

is

a s

urf

ace

an

aly

sis

of

gra

ph

itic

ca

rbo

ns

3

.2.

An

aly

tica

l st

rate

gy

an

d s

am

ple

pre

pa

rati

on

: h

ow

to

min

imiz

e a

na

lyti

cal

art

ifa

ct?

3

.3.

Th

e a

nis

otr

op

ic s

tru

ctu

re o

f g

rap

hit

ic c

arb

on

s a

nd

po

lari

zati

on

eff

ect

s

3

.4.

Dis

pe

rsiv

ity

of

the

de

fect

pe

aks

an

d c

ho

ice

of

a l

ase

r w

ave

len

gth

3

.5.

Fit

tin

g s

pe

ctra

: h

ow

to

re

trie

ve q

ua

nti

tati

ve i

nfo

rma

tio

n o

n t

he

str

uct

ure

of

gra

ph

itic

ca

rbo

ns?

3

.6.

Th

e i

ntr

insi

c st

ruct

ura

l h

ete

rog

en

eit

y o

f n

atu

ral

gra

ph

itic

ca

rbo

ns

4.

Ap

pli

cati

on

s o

f R

am

an

sp

ect

rosc

op

y t

o t

he

stu

dy

of

na

tura

l g

rap

hit

ic c

arb

on

s

4

.1.

Ca

rbo

niz

ati

on

/gra

ph

itiz

ati

on

du

rin

g t

err

est

ria

l d

iag

en

esi

s/m

eta

mo

rph

ism

4

.2.

Gra

ph

itic

ca

rbo

ns

an

d f

luid

-ro

ck i

nte

ract

ion

s

4

.3.

Gra

ph

itic

ca

rbo

ns

as

tra

ces

of

life

in

th

e g

eo

log

ica

l re

cord

4

.4.

Gra

ph

itic

ca

rbo

ns

an

d c

osm

och

em

istr

y

4

.5.

Gra

ph

itic

ca

rbo

ns

an

d e

nv

iro

nm

en

tal

Sci

en

ces

5.

Co

ncl

usi

on

B

eys

sac

& L

azz

eri

EM

U N

ote

s in

Min

era

log

y 2

01

2

Page 3: Applications of Raman spectroscopy to the study of ...

Gra

ph

itic

ca

rbo

ns

are

am

orp

ho

us-

lik

e o

r tu

rbo

stra

tic

or

mic

rocr

yst

all

ine

or

Mo

no

cry

sta

llin

e…

op

aq

ue

(h

igh

ext

inct

ion

co

eff

icie

nt

for

vis

ible

lig

ht)

=>

Lo

w p

en

etr

ati

on

of

lase

r, <

20

0 n

m (

Lesp

ad

e e

t a

l. 1

98

4)

an

iso

tro

pic

(in

cre

asi

ng

an

iso

tro

py

wit

h g

rap

hit

iza

tio

n)

=>

Po

ssib

le e

ffe

ct o

f sa

mp

le o

rie

nta

tio

n v

s la

ser

po

lari

zati

on

fra

gil

e (

ea

sily

cle

ave

d a

lon

g t

he

gra

ph

en

e l

aye

rs)

he

tero

ge

ne

ou

s (i

n t

erm

s o

f st

ruct

ure

an

d c

he

mis

try

)

Page 4: Applications of Raman spectroscopy to the study of ...

Ch

em

ica

l a

nd

str

uct

ura

l

evo

luti

on

of

carb

on

ace

ou

s

ma

teri

al

du

rin

g b

uri

al

Re

vie

w b

y

Va

nd

en

bro

uck

e &

La

rge

au

,

Org

an

ic G

eo

che

mis

try (

20

07

)

Page 5: Applications of Raman spectroscopy to the study of ...

Ferr

ari

and R

obert

son, P

hys. R

ev. B

, 2000

Quantify

ing t

he d

egre

e o

f gra

phitiz

atio

n

Tuin

str

a &

Koenig

, J. C

hem

. P

hys., 1

970

For

a r

evi

ew

: B

eys

sac

& L

azz

eri

EM

U N

ote

s in

Min

era

log

y 2

01

2

Page 6: Applications of Raman spectroscopy to the study of ...

Pro

tocol fo

r R

am

an a

naly

sis

of gra

phitic

carb

on m

ate

rials

Ra

ma

n s

pe

ctro

sco

py

is

a s

urf

ace

an

aly

sis

for

gra

ph

itic

ca

rbo

ns

Dis

pe

rsiv

ity

of

the

de

fect

ba

nd

s =

> c

on

sta

nt

lase

r l

(5

14

.5 n

m)

Lase

r-in

du

ced

he

ati

ng

=>

lo

w-l

ase

r p

ow

er

(<0

.5m

W @

51

4.5

nm

)

Sa

mp

le o

rie

nta

tio

n v

ers

us

lase

r p

ola

riza

tio

n =

> n

ot

a p

rob

lem

exc

ep

t fo

r

gra

ph

ite

mo

no

crys

tals

Str

uct

ura

l d

efe

cts

ind

uce

d b

y s

am

ple

pre

pa

rati

on

(e

.g.

po

lish

ing

) =

> a

na

lysi

s b

elo

w

a t

ran

spa

ren

t m

ine

ral

wit

hin

th

e t

hin

-se

ctio

n t

hic

kn

ess

Intr

insi

c st

ruct

ura

l h

ete

rog

en

eit

y o

f n

atu

ral

gra

ph

itic

ca

rbo

ns

=>

to

be

do

cum

en

ted

Ext

ract

ing

qu

an

tita

tive

in

form

ati

on

fro

m t

he

Ra

ma

n s

pe

ctra

=>

Pe

ak

fit

tin

g

Se

e B

eys

sac

& L

azz

eri

, E

MU

No

tes

in M

ine

ralo

gy

an

d r

efe

ren

ces

the

rein

Page 7: Applications of Raman spectroscopy to the study of ...

Dis

pe

rsiv

ity

of

the

de

fect

ba

nd

s: p

ract

ica

l co

nse

qu

en

ces

po

siti

on

an

d r

ela

tive

in

ten

siti

es=

f(l

lase

r)

Fro

m P

ime

nta

et

al.

(2

00

7)

Page 8: Applications of Raman spectroscopy to the study of ...

Ca

nca

do

et

al.

(A

pp

lie

d P

hys

ics

Lett

ers

20

06

)

Dis

pe

rsiv

ity

of

the

de

fect

ba

nd

s: p

ract

ica

l co

nse

qu

en

ces

po

siti

on

an

d r

ela

tive

in

ten

siti

es=

f(l

lase

r)

Sp

ect

ra t

o b

e c

om

pa

red

MU

ST

be

ob

tain

ed

at

the

ve

ry s

am

e l

ase

r w

ave

len

gth

Page 9: Applications of Raman spectroscopy to the study of ...

51

4 n

m

10

00

1

50

0

20

00

2

50

0

30

00

Ba

sal

pla

ne

Ed

ge

pla

ne

ll

Ed

ge

pla

ne

^

15

82

16

24

1

36

6

27

27

32

48

24

40

78

0 n

m

10

00

1

50

0

20

00

2

50

0

30

00

15

80

13

22

86

3

16

15

26

46

32

44

63

3 n

m

Ra

ma

n S

hif

t (c

m-1

)

10

00

1

50

0

20

00

2

50

0

30

00

15

81

13

44

16

49

16

20

24

54

26

85

23

28

86

4

Sa

mp

le o

rie

nta

tio

n v

ers

us

lase

r p

ola

riza

tio

n

Tan

et

al.

20

04

No

sig

nif

ica

nt

eff

ect

@ 5

14

nm

fo

r g

rap

hit

ic C

/ m

icro

crys

tall

ine

gra

ph

ite

For

gra

ph

ite

mo

no

crys

tal,

use

a c

ircu

lar

po

lari

zati

on

fo

r th

e l

ase

r a

nd

me

asu

re s

am

e

ori

en

tati

on

Page 10: Applications of Raman spectroscopy to the study of ...

Str

uct

ura

l d

efe

ct i

nd

uce

d b

y s

am

ple

pre

pa

rati

on

(p

oli

shin

g,

cru

shin

g,

che

mis

try

…)

e.g

. P

ast

eri

s (A

pp

lie

d S

pe

ctro

sco

py 1

98

9),

Be

yssa

c e

t a

l. (

20

03

)

Gra

ph

itic

ca

rbo

ns

are

bla

ck,

op

aq

ue

ma

teri

als

, a

nd

as

such

ha

ve a

hig

h e

xtin

ctio

n

coe

ffic

ien

t fo

r v

isib

le l

igh

t. T

he

dir

ect

co

nse

qu

en

ce i

s th

at,

in

th

e v

isib

le r

an

ge

, th

e

pe

ne

tra

tio

n o

f th

e l

ase

r in

gra

ph

itic

ca

rbo

ns

is v

ery

lo

w.

Usi

ng

C f

ilm

s w

ith

a w

ell

con

stra

ine

d t

hic

kn

ess

de

po

site

d b

y c

he

mic

al

vap

or

de

po

siti

on

on

a c

oru

nd

um

sub

stra

te,

Lesp

ad

e e

t a

l. (

19

84

) e

stim

ate

d t

he

arg

on

la

ser

(2.4

1e

V,

51

4 n

m)

pe

ne

tra

tio

n d

ep

th a

t a

bo

ut

10

0-2

00

nm

.

Page 11: Applications of Raman spectroscopy to the study of ...

Str

uct

ura

l d

efe

ct i

nd

uce

d b

y s

am

ple

pre

pa

rati

on

(p

oli

shin

g,

cru

shin

g,

che

mis

try

…)

Tra

nsp

are

nt

min

era

l g

rap

hit

e

lase

r la

ser

po

lish

ed

N

on

po

lish

ed

A

na

lysi

s b

elo

w a

tra

nsp

are

nt

min

era

l w

ith

in t

he

th

in-s

ect

ion

thic

kn

ess

Þ N

o s

tru

ctu

ral

ma

pp

ing

on

po

lish

ed

sa

mp

le.

Na

sda

la e

t a

l. (

EM

U n

ote

s 2

00

4)

Be

rna

rd e

t a

l. (

EP

SL

20

07

)

Page 12: Applications of Raman spectroscopy to the study of ...

Eve

rall

et

al.

(C

arb

on

19

91

)

Lase

r-in

du

ced

he

ati

ng

Ph

oto

-oxy

da

tio

n o

f g

rap

hit

ic C

un

de

r th

e l

ase

r in

air

Do

wn

shif

tin

g o

f G

an

d D

po

siti

on

Þ M

ust

use

lo

w-l

ase

r e

ne

rgy

(< 0

.5m

W @

51

4.5

nm

)

Page 13: Applications of Raman spectroscopy to the study of ...

Ra

ma

n s

pe

ctro

sco

py

of

gra

ph

itic

ca

rbo

ns

1st

an

d 2

nd o

rde

r

G b

an

d v

s. D

efe

ct b

an

ds

Do

ub

le-r

eso

nn

an

ce R

am

an

th

eo

ry f

or

the

de

fect

Ba

nd

s (T

ho

mse

n &

Re

ich

20

00

; se

e B

eys

sac

& L

azz

eri

EM

U n

ote

s in

Min

era

log

y f

or

a r

ev

iew

)

Beyssac

&Lazzeri

EM

UN

ote

s2012

Page 14: Applications of Raman spectroscopy to the study of ...

Ra

ma

n v

ers

us

XR

D (

tra

ckin

g 3

D o

rde

rin

g)

Lesp

ad

e e

t a

l. (

Ca

rbo

n 1

98

4)

Pim

en

ta e

t a

l. (

20

07

)

Sp

liti

ng

of

the

2D

ba

nd

in

dic

ate

s

Loca

l 3

D A

BA

B s

tack

ing

Page 15: Applications of Raman spectroscopy to the study of ...

Ra

ma

n v

ers

us

XR

D (

tra

ckin

g 3

D o

rde

rin

g)

Wo

pe

nka

& P

ast

eri

s (A

m M

in 1

99

3)

Be

rna

rd e

t a

l. (

Ca

rbo

n 2

01

0)

+ S

TX

M-X

AN

ES

At

the

C k

-ed

ge

Page 16: Applications of Raman spectroscopy to the study of ...

Sadezky e

t al.,

Carb

on, 2005

Schopf et

al. (

Astr

obio

logy 2

005)

Bonal et

al. (

GC

A 2

006)

Zic

kle

r et

al. (

Carb

on 2

006)

Fit

tin

g s

pe

ctra

of

gra

ph

itic

ca

rbo

ns

Page 17: Applications of Raman spectroscopy to the study of ...

Fit

ing

sp

ect

ra o

f

gra

ph

itic

ca

rbo

ns

Exa

mp

les

of

pe

ak

-fit

tin

g p

roce

du

res

for

Ra

ma

n s

pe

ctra

of

gra

ph

itic

carb

on

s. a

) P

ea

k-f

itti

ng

in

ca

se o

f a

very

dis

ord

ere

d g

rap

hit

ic c

arb

on

usi

ng

5 b

an

ds

wit

h p

ure

Lo

ren

tzia

n

sha

pe

. b

) P

ea

k-f

itti

ng

in

ca

se o

f a

gra

ph

itic

ca

rbo

n u

sin

g 3

ba

nd

s w

ith

Vo

igt

pro

file

(m

ix G

au

ssia

n-

Lore

ntz

ian

). N

ote

th

at

in a

ll c

ase

s

no

a p

rio

ri r

est

rict

ion

is

imp

ose

d o

n

the

ba

nd

po

siti

on

, F

WH

M o

r

inte

nsi

ty.

Th

ick

gre

y l

ine

is

the

me

asu

red

sp

ect

rum

, b

lack

lin

e i

s

the

mo

de

led

sp

ect

rum

, g

rey

da

she

d

lin

es

are

th

e p

ea

ks m

od

ele

d.

Ext

ract

ion

of

qu

an

tita

tive

pa

ram

ete

rs (

FW

HM

, p

osi

tio

n,

aa

tio

s…)

Ca

uti

on

wit

h I

D /

IG r

ati

o

Be

yssa

c e

t a

l. 2

00

3;

Be

yssa

c &

La

zze

ri 2

01

2

Page 18: Applications of Raman spectroscopy to the study of ...

!"#$%&%'()**%+"'

',!

-!./'.012/'3-!.'435"67'-)+"8'9:/';+)5#%

'

!"#$%&'&($)*#+,-.'$/0$1-&*"2,#3$,"#/-4$

<'

=+)>$"?%@'ABC%&'DB+'8>E'#)+FB58'

-+%8%5?'G5"HG%'D%)?G+%8'4?$%B+%I#)&'G5C%+8?)5C"5J'5B?'%)8K:'

L%+K'M%&&'8?GC"%C'

' N%+%@'"5?+BCG#IB5'?B'?$%'OBGF&%'1%8B5)5#%'

Page 19: Applications of Raman spectroscopy to the study of ...

PQ#"I5J'&)8%+'

2#)R%+%C'

&"J$?'

ν('

ν2'

ν('

ν(Sν>'

ν(Tν>'

1)A)5'8$"U'

,5?%58"?K'

%&'&($)+&5#-2(1$

42?BV%8:'

4W5IS2?BV%8:'

;+%HG%5#K')5)&"*%+@'

E'

Page 20: Applications of Raman spectroscopy to the study of ...

627-&8/(&9$%&'&($

>$B5B5'

4P5%+JK'''XX'ABA%5?GA:'

,5#"C%5?'("J$?'

Sca

tter

ed l

ight@'

c:

Sp

eed o

f li

ght

h:

Pla

nck

const

ant

�=

h/(2π)

-%+D%#?'#+K8?)&@'

P5%+JK'T'A

BA%5?GA'#B58%+6)IB5'

q=

νq/c≃

0

!B8?'"5?%58%'>+B#%88%8@'B5%S>$B5B5'%Q#"?)IB5':Y;$

' Z?$%+'>B88"F&%'>+B#%88%8@'

'''[MBS>$B5B5'%Q#"?)IB5'\:/':'4:];:'

'''O%D%#?S)#I6)?%C'B5%S>$B5B5'4:];:'

hνL

//

hνL/c

hνS

//

hνS/c

hνq

//

�q

^'

hνL/c=

hνS/c+

�νq

νL=

νS+νq

q

Page 21: Applications of Raman spectroscopy to the study of ...

<-&*"2,#$%&'&($)*#+,-&$

B5%'>$B5B5':Y;$

Γ'P

EJ'

='W_ <'

=@'`';"+8?SB+C%+'a'1)A)5'

' OXEO@'OBGF&%'+%8B5)5#%''

O"8B+C%+%C'

!B5B#+K8?)&'

B5%'>$B5B5':];$

4C%D%#?S)#I6)?%C:'

[MB'>$B5B58'\:/:'4:];:'

)?%C:'

$B5B5':

B5B

b'

Page 22: Applications of Raman spectroscopy to the study of ...

>"4$&-#$,"#$?@A?$*#&B)$)/$.(2:.#C$

W5BA)&BG8&K'$"J$'"5?%58"?K'

0)++BM'>%)V/'M"?$'M%&&'C%c5%C'8$)>%'

;+%HG%5#K'C%>%5C8'B5'?$%'&)8%+'%5%+JK'

OBGF&%'+%8B5)5#%'

4[$BA8%5'd'1%"#$'-1('Eeee:'

f'

;"J7'D+BA'-"A

%5?)'%?')&7'-..-'4Eeeg:'

Page 23: Applications of Raman spectroscopy to the study of ...

D.&(,.'$'

#+"&(2+)3$7&)2+$+/(+#*,)$

P&%A%5?)+K'

%Q#"?)IB58'

"5')'8B&"C'

S&"J$?'

' S>$B5B5"#'

' S%&%#?+B5"#'

|a〉@'8?)?%'BD'?$%'8K8?%A'

@'%5%+JK'

ǫa

=+BG5C'8?)?%'!

'%Q#"?)IB58'

ε :@'h)5C'8?+G#?G+%'4?$%'%5%+J"%8')5'%&%#?+B5'"8')&&BM%C'?B'$)6%:'

=+BG5C'8?)?%@'&BM%8?'F)5C8')+%'B##G>"%C'

''''''''''''''''''''''''''$"J$%8?'F)5C8')+%'%A>?K'

PQ#"?)IB5@'#+%)IB5'BD')5'%&%#?+B5X$B&%'>)"+'

L%+I#)&'?+)58"IB5'!

*%+B'A

BA%5?GA'

i$)?'"8')5'%&%#?+B5"#'%Q#"?)IB5j'

ǫq

q

4'P5%+JK''XX'A

BA%5?GA':'

hνq

//

�q

hνL

//

hνL/c

9'

Page 24: Applications of Raman spectroscopy to the study of ...

D.&(,.'$'

#+"&(2+)3$7&)2+$+/(+#*,)$

P&%A%5?)+K'

%Q#"?)IB58'

"5')'8B&"C'

S&"J$?'

' S>$B5B5"#'

' S%&%#?+B5"#'

|a〉@'8?)?%'BD'?$%'8K8?%A'

@'%5%+JK'

ǫa

=+BG5C'8?)?%'!

'%Q#"?)IB58'

hνq

//

�q

hνL

//

hνL/c

|a〉=

|νL〉

⊗|ph〉

⊗|el〉

1)A)5@'

!'

|i〉=

|νL〉

⊗|G〉

⊗|G〉

|f〉=

|νS〉

⊗|νp〉

⊗|G〉

g'

Page 25: Applications of Raman spectroscopy to the study of ...

E#-,.-7&8/($,"#/-4$FG),$/-H#-I$

,5?%+)#IB5'>B?%5I)&''''!

'4%7J7@'%&%#?+B5X&"J$?k'

%&%#?+B5X>$B5B5k'

%&%#?+B5XC%D%#?8:'

VPif

4[+)58"IB5'>+BF)F"&"?K:'

;%+A

"'=B&C%5'+G&%'

4h)8"#')88GA>IB5@'

L'"8'8A

)&&:'

〈fVi〉

.BA>&%Q'5GAF%+'M$"#$'HG)5Ic%8'?$%'"5?%+)#IB5'F%?M

%%5'"')5C'D'

4&"5%)+'"5'L'!

'<8?'B+C%+:'

δ(ǫ)=

0for

ǫ�=

0⇒

ǫi=

ǫf

4#B58%+6)IB5'BD'%5%+JK:'

Pif=

2π �|〈iVf〉|2δ(ǫ

i−

ǫf)

l'

Page 26: Applications of Raman spectroscopy to the study of ...

E#-,.-7&8/($,"#/-4$FJ-H$/-H#-I$

∑ a

@2GA'B5')&&'?$%'>B88"F&%'%Q#"?)IB58'

' @2A)&&'+%)&'5GAF%+'

γ

iW10,0=@',5'&"?%+)?G+%'?$"8'"8'#)&&%C'`'c+8?SB+C%+'a'1)A)5'

1)A)5'8#)R%+"5J'4B5%':Y;'>$B5B5:'

^'#B58%#GI6%'`'6"+?G)&'?+)58"IB58'a@'

i→

aa→

bb→

f

Pif=

2π �

∣ ∣ ∣ ∣ ∣ ∣∑ a,b

〈iVa〉〈aVb〉〈bVf〉

(ǫi−

ǫa−

iγ)(ǫi−

ǫb−iγ)

∣ ∣ ∣ ∣ ∣ ∣2

δ(ǫ

i−

ǫf)

("J$?')F8B+>IB5'

4%&%#?+B5X$B&%'#+%)IB5:'

P&%#?+B5X>$B5B5'8#)R%+"5J'

4>$B5B5'%Q#"?)IB5:'

("J$?'%A"88"B5'

4%&%#?+B5X$B&%'+%#BAF"5)IB5:'

m'

ǫq

q

Page 27: Applications of Raman spectroscopy to the study of ...

E#-,.-7&8/($,"#/-4$FK,"$/-H#-I$

Pif=

2π �

∣ ∣ ∣ ∣ ∣ ∣∑ a,b,c

〈iVa〉〈aVb〉〈bVc〉〈cVf〉

(ǫi−

ǫa−iγ)(ǫi−

ǫb−

iγ)(ǫi−

ǫc−iγ)

∣ ∣ ∣ ∣ ∣ ∣2

δ(ǫ

i−

ǫf)

:$

L:$

i→

aa→

b

1)A)5'8#)R%+"5J'4B5%':];'>$B5B5/'C%D%#?')#I6)?%C:'

b'`'6"+?G)&'?+)58"IB58'a@'

("J$?')F8B+>IB5'

P&%#?+X>$B5'8#)R%+"5J'

("J$?'%A"88"B5'

O%D%#?'8#)R%+"5J'

b→

cc→

f

b→

c

P&%#?+B5X>$B5B5'8#)R%+"5J'

[MB'>$B5B58'SH/H@'

<e'

Page 28: Applications of Raman spectroscopy to the study of ...

E&-8&9$).''&-43$

-%+?G+F)IB5'?$%B+K'48?)5C)+C'?%Q?FBBV'?BB&:@'

^+C'B+C%+'!'%Q#"?)IB5'BD'B5%':Y;'>$B5B5'

b?$'B+C%+'!'%Q#"?)IB5'BD'?M

BS>$B5B58'

'''''''''''''''''''''''%Q#"?)IB5'BD'B5%':];'>$B5B5'4C%D%#?S)#I6)?%C:''

i$K')+%'?$%'OXEO'>%)V8'8B'"5?%58%j'

i$K')+%'?$%K'8A)&&SM

"C?$'M%&&'C%c5%C'>%)V8j'

i$K'CB'?$%K'C"8>%+8%'M"?$'?$%'()8%+'%5%+JKj'

OBGF&%'+%8B5)5#%'4[$BA8%5'd'1%"#$/'-1('Eeee:'

<<'

Page 29: Applications of Raman spectroscopy to the study of ...

%#)/(&(,$%&'&($

Pif=

2π �

∣ ∣ ∣ ∣ ∣ ∣∑ a,b

〈iVa〉〈aVb〉〈bVf〉

(ǫi−

ǫa−

iγ)(ǫi−

ǫb−iγ)

∣ ∣ ∣ ∣ ∣ ∣2

δ(ǫ

i−

ǫf)

!"'4%&%#?+B5"#'J)>:@'A

"5"A

GA'%5%+JK'DB+'%&%#?+B5"#'%Q#"?)IB5'

######!"]e'!

'"58G&)?B+8X8%A"#B5CG#?B+8'

######!"Ye'!

'A%?)&8X8%A"SA%?)&8'

1)A)5@'

,5'?$%'6"+?G)&'?+)58"IB58'?$%'%5%+JK'"8'5B?'5%#%88)+"&K'#B58%+6%C'4$%"%'ε &'#)5'F%']'ε':'

'''''''''''''''''''''''''''''''''''''''''''''''''i

$%5'ε&nε '

'!'`'+%8B5)5#%'a'

' !"'oo'(ν)'@'0B5S1%8B5)5?'1)A)5'

!"'Y'e'@'1)A)5'"8')&M)K8'+%8B5)5?'

' =+)>$"?%@'!"Ye'!

'1)A)5'"8')&M)K8'+%8B5)5?'4?$%'>$K8"#8'"8'AB+%'#BA>&%Q:'

<E'

ǫq

q

Page 30: Applications of Raman spectroscopy to the study of ...

<-&*"2,#3$7&(H$),-.+,.-#$

PA>?K'

Z##G>"%C'

=+)>$%5%XJ+)>$"?%@'6%+K'8"A

"&)+'F)5C'8?+G#?G+%')5C'6%+K'8"A

"&)+'1)A)5'8>%#?+)7'

"'Y'p'BD'%&%#?+B5"#'8?)?%8')?')'J"6%5'%5%+JK'

ε *'Y';%+A

"'&%6%&'

!%?)&8@'

2%A"#B5CG#?B+8'

,58G&)?B+8@'

ǫF

g

ǫF

g

ǫF

g

=+)>$"?%XJ+)>$%5%@'

48%A"SA%?)&8:'

πq'F)5C8@'&BM%8?'%A>?K'

' π'F)5C8@'$"J$%8?'B##G>"%C'

'

[$%'`'J)>'a'"8'*%+B'"5'

B5&K'B5%'>B"5?'4=:'BD'

?$%'h+"&&BG"5'*B5%'

P5%+JK'

<^'

Page 31: Applications of Raman spectroscopy to the study of ...

?/.79#$%#)/(&(+#$2($1-&*"2,#@1-&*"#(#$

KK

Energy

(1)

(2)

(3)

(4)

*

kk+q

k!

k!*

' 4<: ("J$?')F8B+>IB5'

4E: P&%#?+B5'8#)R%+"5J'M"?$')'C%D%#?'

4^: P&%#?+B5S>$B5B5'8#)R%+"5J'

4b: ("J$?'%A"88"B5'

O'>%)V'

4O%D%#?S)#I6)?%C'

b?$'B+C%+'>+B#%88:'

,5'>+"5#">&%@')&&'?$%'>B88"F&%'>+B#%88%8'$)6%'?B'F%'#B58"C%+%C'

<b'

Page 32: Applications of Raman spectroscopy to the study of ...

?/.79#$%#)/(&(+#$2($1-&*"2,#@1-&*"#(#$

KK

Energy

(1)

(2)

(3)

(4)

*

kk+q

k!

k!*

' 4<: ("J$?')F8B+>IB5'

4E: P&%#?+B5'8#)R%+"5J'M"?$')'C%D%#?'

4^: P&%#?+B5S>$B5B5'8#)R%+"5J'

4b: ("J$?'%A"88"B5'

O'>%)V'

4O%D%#?S)#I6)?%C'

b?$'B+C%+'>+B#%88:'

,5'J%5%+)&@')&&'?$%'>B88"F&%'>+B#%88%8'$)6%'?B'F%'#B58"C%+%C'

'

[$BA8%5'd'1%"#$'4Eeee:@'[$%'"A>B+?)5?'>+B#%88%8'?)V%'>&)#%'

B5&K'DB+'#%+?)"5'6)&G%8'BD'V')5C'H'48%&%#?%C'FK'?$%'#B58%+6)IB5'

BD'%5%+JK'"5'?$%'6"+?G)&'?+)58"IB58:'

,5'J%5%+)&@')&&'?$%'>B88"F&%'>+B#%88%8'$)6%'?B'F%#B58"C%+%C

<f'

Page 33: Applications of Raman spectroscopy to the study of ...

?/.79#$%#)/(&(+#$2($1-&*"2,#@1-&*"#(#$

KK

Energy

(1)

(2)

(3)

(4)

*

kk+q

k!

k!*

' 4<: ("J$?')F8B+>IB5'

4E: P&%#?+B5'8#)R%+"5J'M"?$')'C%D%#?'

4^: P&%#?+B5S>$B5B5'8#)R%+"5J'

4b: ("J$?'%A"88"B5'

O'>%)V'

4O%D%#?S)#I6)?%C'

b?$'B+C%+'>+B#%88:'

ǫk,π

∗−

ǫk,π

=hνL

ǫk+q,π

∗=

ǫk,π

!'2%&%#?8'B$

!'2%&%#?8':$

<9'

Page 34: Applications of Raman spectroscopy to the study of ...

?/.79#$%#)/(&(+#$2($1-&*"2,#@1-&*"#(#$

''''''''''''''''''''''''''''''OBGF&%'+%8B5)5#%'%Q>&)"58@'

' SW5BA)&BG8&K'$"J$'"5?%58"?K'BD'OXEO'>%)V8'

S[$%K')+%'M%&&SC%c5%C'8A)&&SM

"C?$'>%)V8'45B?'F+B)C'F)5C8:'

S[$%')#?G)&'B+"J"5'BD'?$%'C%D%#?'CB%8'5B?'>&)K')'+B&%'

'

KK

Energy

(1)

(2)

(3)

(4)

*

kk+q

k!

k!*

<g'

Page 35: Applications of Raman spectroscopy to the study of ...

?/.79#$%#)/(&(+#$2($1-&*"2,#@1-&*"#(#$

''''''''''''''''''''''''''''''OBGF&%'+%8B5)5#%'%Q>&)"58@'

' SW5BA)&BG8&K'$"J$'"5?%58"?K'BD'OXEO'>%)V8'

S[$%K')+%'M%&&SC%c5%C'8A)&&SM

"C?$'>%)V8'45B?'F+B)C'F)5C8:'

S[$%')#?G)&'B+"J"5'BD'?$%'C%D%#?'CB%8'5B?'>&)K')'+B&%'

S[$%'>%)V8'8$"U'FK'#$)5J"5J'?$%'&)8%+'%5%+JK'

'

KK

Energy

*

q

hL

KK

Energy

*

q’

hL’

<l'

Page 36: Applications of Raman spectroscopy to the study of ...

M5-27.8/($/0$,"#$%&'&($*#&B)$

KK

Energy

*

KK

Energy

*K

K

Energy

*

KK

Energy

*

40

0

80

0

12

00

16

00

Phonon frequency (cm-1

)

KM

D'

D'

DD

D''

KK

<m'

Energy

KK

K

Energy

*

KK

Page 37: Applications of Raman spectroscopy to the study of ...

M5-27.8/($/0$,"#$%&'&($*#&B)$

=+)>$"?%'A

B5B#+K8?)&'

O"8B+C%+%C'J+)>$"?%'

OTO__'

EO_'

40

0

80

0

12

00

16

00

Phonon frequency (cm-1

)K

M

D'

D'

DD

D''

(BM%8?SB+C%+@'

='!

'<fle'#A

S<'

' OBGF&%'+%8B5)5?@'

<:'O%D%#?S)#I6)?%C@'

''''O''!'<^fe'#A

S<'

''''O_'!'<9Ee''

' E:'[MBS>$B5B5@'

''''OTO__'!

'Ebfe'#A

S<'

''''EO''''''!'Egee'

''''EO_'''''!'^Ebe''

λ('Y'f<b'5A'

Ee'

G

16

00

G

Page 38: Applications of Raman spectroscopy to the study of ...

%&'&($&)$&$,//9$,/$'

#&).-#$H2)/-H#-$

( )Y'

((((((((((((((((((((((( ))))))))))))))))))))))))))))))))))))Y

;"J7'D+BA'-"A

%5?)'%?')&'-..-'Eeeg'

.)5'M%'HG)5IDK'?$%'C"8B+C%+'?$+BGJ$'

?$%'O'>%)Vj'

ID

IG

1

La

) ''Y'#+K8?)&&"?%'8"*%'

[G"58?+)'d'rB%5"J'+%&)IB5'4<mge:@'

E<'

='

O' Y'

Page 39: Applications of Raman spectroscopy to the study of ...

6&92H2,4$92'

2,)$/0$,"#$!=$-#9&8/($

.)5#)CB'%?')&7'Eee9';%++)+"'d'1BF%+?8B5'-1h'Eeee'

ID/IG∝

1/La

B5&K'DB+'

La>

2nm

C%>%5C8')&8B'B5'ν

('

ID/IG

[$%'O'>%)V'#)5'F%')#I6)?%C'FK'

B?$%+'8BG+#%8'BD''C"8B+C%+s'

-B"5?SC%D%#?8'"5CG#%C'FK'

,B5SFBAF)+CA%5?'

(G##$%8%'%?')&7'.)+FB5'Ee<e'

EE'

Page 40: Applications of Raman spectroscopy to the study of ...

A?$)"&*#$&(H$),&+B2(1$/-H#-$

()8>)C%'%?')&7/'.)+FB5'<mlb'

.)5#)CB'%?')&7/'.)+FB5'Eeel'

.+K8?)&&"5%'

[G+FB8?+)I#'

KK

Energy

*

KK

Energy

*

;%++)+"'%?')&7/'-1('Eee9'

=+)>$"?%@'

=+)>$%5%@'

1)A)5'8$"U'4#A

S<:'

[$%'EO'8$)>%'>+B6"C%8'"5DB+A

)IB5'B5'?$%'8?)#V"5J'B+C%+'

E^'

Page 41: Applications of Raman spectroscopy to the study of ...

N/(+9.)2/()$

L%5%*G%&)'%?')&7'-1h'Ee<<'

Eeee@'[$BA8%5'd'1%"#$'!

'%Q>&)5)IB5'BD'?$%'J%5%+)&'#$)+)#?%+"8I#8'BD'?$%'8>%#?+)'

0BM)C)K8@'HG)5I?)I6%')>>+B)#$'?B'

C%8#+"F%'1)A)5'8>%#?+)'"5'#B5?+B&&%C'

%Q>%+"A%5?)&'8"?G)IB58'

.$)+)#?%+"*)IB5'BD'5)?G+)&'8)A>&%8'"8'8I&&'$%)6"&K'F)8%C'B5'>$%5BA%5B&BJ"#)&'ABC%&'

[$"8'?)&V@'"5?+BCG#IB5'?B'?$%'OBGF&%'1%8B5)5?'1)A)5'

"5'J+)>$"?%'4ABC%&'8>E'#)+FB5'8K8?%A:''

Eb'