14
第5章 回折条件 Diffraction condition 第4章で,熱振動の効果が無視できないとしても,結晶全体の平均の構造因子を求める ことができて,以下の一連の式で表されるということを導きました。 F total ( r K ) = G( r K )F ( r K ) (5.1) G( r K ) exp 2πi r K ξ r a + η r b + ς r c ( ) [ ] ξ , η, ζ (5.2) F ( r K ) = f j ( r K )T j ( r K )exp 2πi r K r r j ( ) j =1 M 結晶構造因子 (5.3) f j ( r K ) ρ j ( r r )exp 2πi r K r r ( ) dv R 3 原子散乱因子 (5.4) T j ( r K ) g j ( r r )exp 2πi r K r r ( ) dv R 3 温度因子(原子変位因子) (5.5) ただし,単位構造の中に M 個の原子が含まれているとして, ρ j ( r r ) は単位構造に含まれ j 番目の原子の電子密度を表す関数, g j ( r r ) j 番目の原子の位置の確率分布を表す 関数であるとします。 5-1 ラウエ関数とラウエ条件 Laue function & Laue condition この節の内容の大部分は菊田惺志著「X線回折・散乱技術 上」(東京大学出版会, 1992 年)から引用したものであることをはじめにお断りしておきます。

第5章 回折条件 Diffraction conditionida/education/structureanalysis/5/...第5章 回折条件 Diffraction condition 第4章で,熱振動の効果が無視できないとしても,結晶全体の平均の構造因子を求める

Embed Size (px)

Citation preview

Diffraction condition

Ftotal(r K ) = G(

r K )F(

r K ) (5.1)

G(r K ) exp 2i

r K r a +

r b + r c ( )[ ]

,, (5.2)

F(r K ) = f j (

r K )Tj (

r K )exp 2i

r K r r j( )

j=1

M (5.3)

f j (r K ) j (

r r )exp 2ir K r r ( )dv

R 3 (5.4)

Tj (r K ) g j (

r r )exp 2ir K r r ( )dv

R 3 (5.5)

M

j (r r )

j

g j (r r )

j

Laue function & Laue condition

1992

r a

r b

r c

Na

Nb

Nc

5.1

(5.2)

G(r K )

,

,

5.1

r a ,

r b ,

r c

Na,

Nb ,

Nc

G(r K ) = exp 2i

r K r a +

r b + r c ( )[ ]

=0

N c1

=0

N b1

=0

N a 1

= exp 2ir K r a ( ) exp 2i

r K

r b ( ) exp 2i

r K r c ( )

=0

N c1

=0

N b1

=0

N a1 (5.6)

exp 2ir K r a ( )

=0

N a1

=1+ exp 2ir K r a ( ) + exp 4i

r K r a ( ) +L+ exp 2 Na 1( )i

r K r a [ ]

1,

exp 2ir K r a ( )

x jj=0

n1 = 1 x

n

1 x

exp 2ir K r a ( )

=0

N a1 =

exp 2iNar K r a ( ) 1

exp 2ir K r a ( ) 1

(5.7)

Ftotal(r K )

2= G(

r K )

2F(

r K )

2 (5.8)

(5.7)

exp 2ir K r a ( )

=0

N a 1

2

=exp 2iNa

r K r a ( ) 1

2

exp 2ir K r a ( ) 1

2

=exp 2iNa

r K r a ( ) 1[ ] exp 2iNa

r K r a ( ) 1[ ]

exp 2ir K r a ( ) 1[ ] exp 2i

r K r a ( ) 1[ ]

=2 2cos 2Na

r K r a ( )

2 2cos 2r K r a ( )

=1 cos 2Na

r K r a ( )

1 cos 2r K r a ( )

=sin2 Na

r K r a ( )

sin2 r K r a ( )

(5.9)

G(K) 2 =sin2 Na

r K r a ( )

sin2 r K r a ( )

sin2 Nbr K

r b ( )

sin2 r K

r b ( )

sin2 Ncr K r c ( )

sin2 r K r c ( )

(5.10)

Laue function

sin2 Nar K r a ( )

sin2 r K r a ( )

r K r a 5.2

r K r a = h

h

1 /Na,

2 /Na,

3 /Na

limx0

sin2 Nax( )sin2 x( )

= Na2 lim

x0

sin Nax( )Nax

2x

sin x( )

2

= Na2 (5.11)

2.52.01.51.00.50.0-0.5

r K r a

sin2N

ar K r

a (

)sin

2

r K r

a (

)

Na2

~ 1Na

5.2

sin2 Nar K r a ( )

sin2 r K r a ( )

,

Na =10

Na2

1 /Na

Na

Na =10

Na2 =100

sin2 Na 3 /2Na( )[ ]sin2 3 / 2Na( )[ ]

=1

sin2 3 /2Na( )[ ]= 4.85

sin2 Na 5 /2Na( )[ ]sin2 5 / 2Na( )[ ]

=1

sin2 5 /2Na( )[ ]= 2.00

Na

Na,

Nb ,

Nc (5.10)

r K r a = hr K

r b = k

r K r c = l

h ,

k ,

l (5.12)

G(r K )

2 NaNbNc( )

2 = N 2 (5.13)

NaNbNc = N (5.12) Laue condition

lattice vectors and reciprocal lattice vectors

r a ,

r b ,

r c

r a * ,

r b * ,

r c *

r a r a * =1 r a r b * = 0 r a r c * = 0

r b r a * = 0

r b

r b * =1

r b r c * = 0

r c r a * = 0 r c r b * = 0 r c r c * =1

(5.14)

r a *

r b

r c

r a 1 (5.12)

r K

r K = hr a * + k

r b * + lr c *

h ,

k ,

l (5.15)

r a ,

r b ,

r c

r a * ,

r b * ,

r c *

r a =axayaz

,

r b =

bxbybz

,

r c =cxcycz

, (5.16)

r a * =ax*

ay*

az*

,

r b * =

bx*

by*

bz*

,

r c * =cx*

cy*

cz*

(5.17)

(5.14)

ax* ay

* az*

bx* by

* bz*

cx* cy

* cz*

ax bx cxay by cyaz bz cz

=

1 0 00 1 00 0 1

(5.18)

r a r b r c ( )

r a *r b * r c *( )

r p =pxpypz

,

r q =qxqyqz

r p r q

r p r q pyqz pzqypzqx pxqzpxqy pyqx

(5.19)

r p r p r q ( ) = px pyqz pzqy( ) + py pzqx pxqz( ) + pz pxqy pyqx( ) = 0 (5.20)

r q r p r q ( ) = qx pyqz pzqy( ) + qy pzqx pxqz( ) + qz pxqy pyqx( ) = 0 (5.21)

r p r q

r p

r q

r p 2 r q 2 = px2 + py

2 + pz2( ) qx2 + qy2 + qz2( )

= px2qx2 + px

2qy2 + px

2qz2 + py

2qx2 + py

2qy2 + pz

2qz2 + pz

2qx2 + pz

2qy2 + pz

2qz2 (5.22)

r p r q ( )2 = pxqx + pyqy + pzqz( )2

= px2qx2 + py

2qy2 + pz

2qz2 + 2pxqx pyqy + 2pyqy pzqz + 2pzqz pxqx (5.23)

r p r q 2 = pyqz pzqy( )2

+ pzqx pxqz( )2

+ pxqy pyqx( )2

= py2qz2 + 2pyqz pzqy + pz

2qy2 + pz

2qx2 2pzqx pxqz + px

2qz2 + px

2qy2 2pxqy pyqx + py

2qx2

(5.24)

r p 2 r q 2 = r p r q ( )2 +r p r q 2 (5.25)

r p

r q

r p r q = r p r q cos

r p r q = r p 2 r q 2 r p 2 r q 2 cos2 = r p r q sin (5.26)

r p r q

r p

r q

r p r q sin

r a ,

r b ,

r c unit cell

r a r b

r a

r b

r a

r b

r a r b

r a r b

r a

r b

1

r a r b ( ) r c

r a r b

r c

r a

r b

V = r a r b ( ) r c

r b

r c

r c

r a

V = r a r b ( ) r c =

r b r c ( ) r a = r c r a ( )

r b (5.27)

r a * =r b r c

V(5.28)

r b * =

r c r a V

(5.29)

r c * =r a

r b

V(5.30)

(5.27) - (5.30)

lattice constants

a ,

b,

c ,

,

,

r a ,

r b ,

r c

a

r a

b

r b

c

r c

r b

r c

r c

r a

r a

r b

ax ,ay ,az ,bx ,by ,bz,cx ,cy ,cz( )

a = r a = ax2 + ay

2 + az2

cos =r b r c bc

=bxcx + bycy + bzcz

bx2 + by

2 + bz2( ) cx2 + cy2 + cz2( )

a,b,c,,,( )

r a X

r b XY Y > 0

r a

r a =a00

(5.31)

r b

r b =

bcosbsin0

(5.32)

r c

r c =cxcycz

(5.33)

r c

r a

r c r a = cacos (5.34)

(5.32) (5.34)

r c r a = cxa (5.35)

cx = c cos (5.36)

r b

r c

r b r c = bc cos (5.37)

(5.33) (5.34)

r b r c = bcx cos + bcy sin

= b c cos cos + cy sin( ) (5.38)

cy =c cos cos cos( )

sin(5.39)

r c

c

cz = c2 cx

2 cy2 (5.40)

cz

V

V = axbycz (5.41)

r a * =ax*

ay*

az*

=

r b r c

V=1V

bycz bzcybzcx bxczbxcy bycx

lattice plane

r K

r K = hr a * + k

r b * + lr c *

h ,

k ,

l

r d hkl* hr a * + k

r b * + lr c * (5.42)

hkl

hkl

hkl Miller index

hkl

h ,

k ,

l

r a h,

r b k,

r c l

r p =r a h

+ xr b k

r a h

+ y

r c l

r a h

x ,

y (5.43)

r p 0 = x0

r b k

r a h

+ y0

r c l

r a h

x0 ,

y0 (5.44)

r p 0

r d hkl*

x0 ,

y0

r p 0 r d hkl* = 0

r d hkl*

hkl

r p

r d hkl*

r d hkl*

x ,

y

r p r d hkl* =1

1r d hkl*

l = 0

hk0

r a h,

r b k

r c

r p =r a h

+ xr b k

r a h

+ y

r c

x ,

y (5.45)

r p 0 = x0

r b k

r a h

+ y0

r c

x0 ,

y0 (5.46)

r p 0 r d hkl* = 0

r p r d hkl* =1

k = 0

h = 0

k = l = 0

h00

r a h

r b

r c

r p =r a h

+ xr b + yr c

x ,

y (5.47)

r p 0 = x0r b + y0

r c

x0 ,

y0 (5.48)

r p 0 r d hkl* = 0

r p r d hkl* =1

h = l = 0

h = k = 0

r d hkl*

hkl

r a * ,

r b * ,

r c *

ax*,ay

*,az*,bx

*,by*,bz

*,cx*,cy

*,cz*( )

hkl

r d hkl* = hax

* + kbx* + lcx

*( )2

+ hay* + kby

* + lcy*( )2

+ haz* + kbz

* + lcz*( )2

(5.49)

crystal structure factor and Miller indices

r r j

r r j = x jr a + y j

r b + z j

r c (5.50)

x j ,

y j ,

z j 0 1 fractional coordinate

r K

r K = hr a * + k

r b * + lr c *

h ,

k ,

l

Fhkl = f jr d hkl*( )Tj

r d hkl*( )exp 2i hx j + ky j + lz j( )[ ]

j=1

M

(5.51)

r d hkl* hr a * + k

r b * + lr c *

f jr d hkl*( ) atomic scattering factor

dhkl

= 2dhkl sinhkl Bragg

hkl

f jsinhkl

Tjr d hkl*( ) atomic displacement factor

anisotropic atomic displacement factor

g j (r r ) = 1

(2 )3/2U11/2U21/2U31/2exp X

2

2U1

Y 2

2U2

Z2

2U3

(5.52)

r p X =pXxpXypXz

,

r p Y =pYxpYypYz

,

r p Z =pZxpZypZz

r r =xyz

r r = Xr p X + Yr p Y + Z

r p Z

Tj (r K ) = g j (

r r )exp 2ir K r r ( )dv

R 3

= g j (r r )exp 2i

r K r r ( )

dXdYdZ

=1

(2 )3/2U11/2U21/2U31/2exp X

2

2U1

Y 2

2U2

Z 2

2U3

exp 2i KX X + KYY + KzZ( )[ ]

dXdYdZ

= exp 2 2 KX2U1 + KY

2U2 + KZ2U3( )[ ]

= exp 2 2 K X KY KZ( )U1 0 00 U2 00 0 U3

KXKYKZ

= exp 2 2 K x Ky Kz( )P tU1 0 00 U2 00 0 U3

P

KxKyKz

= exp 2 2 Kx Ky Kz( )U jKxKyKz

= exp 2 2r K tU j

r K ( ) (5.53)

= exp 2 2 Kx Ky Kz( )U jxx U jxy U jzxU jxy U jyy U jyzU jzx U jyz U jzz

KxKyKz

= exp 2 2 U jxxKx2( + U jyyKy2 + U jzzKz2 + 2U jxyKxKy + 2U jyzKyKz +2U jzxKzKx )][

(5.54)

U j11 U j12 U j13U j12 U j22 U j23U j13 U j23 U j33

=

ax* / a* ay

* / a* az* / a*

bx* /b* by

* /b* bz* /b*

cx* /c* cy

* / c* cz* / c*

U jxx U jxy U jzxU jxy U jyy U jyzU jzx U jyz U jzz

ax* / a* bx

* /b* cx* /c*

ay* / a* by* /b* cy* /c*

az* / a* bz* /b* cz* /c*

=

1 / a* 0 00 1 /b* 00 0 1 / c*

ax* ay

* az*

bx* by

* bz*

cx* cy

* cz*

U jxx U jxy U jzxU jxy U jyy U jyzU jzx U jyz U jzz

ax* bx

* cx*

ay* by

* cy*

az* bz

* cz*

1 / a* 0 00 1 /b* 00 0 1 / c*

U jxx U jxy U jzxU jxy U jyy U jyzU jzx U jyz U jzz

=

ax bx cxay by cyaz bz cz

a* 0 00 b* 00 0 c*

U j11 U j12 U j13U j12 U j22 U j23U j13 U j23 U j33

a* 0 00 b* 00 0 c*

ax ay azbx by bzcx cy cz

=

ax bx cxay by cyaz bz cz

U j11a*2 U j12a

*b* U j13a*c*

U j12a*b* U j22b

*2 U j23b*c*

U j13a*c* U j23b

*c* U j33c*2

ax ay azbx by bzcx cy cz

r K = hr a * + k

r b * + lr c *

Tj (r K )

= exp 22 U j11h2a*2 + U j22k

2b*2 + U j33l2c*2([

+2U j12hka*b* + 2U j13hla

*c* + 2U j23klb*c* )]

B11 B12 B13B12 B22 B23B13 B23 B33

= 22ax* ay

* az*

bx* by

* bz*

cx* cy

* cz*

Uxx Uxy UzxUxy Uyy UyzUzx Uyz Uzz

ax* bx

* cx*

ay* by

* cy*

az* bz

* cz*

Uxx Uxy UzxUxy Uyy UyzUzx Uyz Uzz

=122

ax bx cxay by cyaz bz cz

B11 B12 B13B12 B22 B23B13 B23 B33

ax ay azbx by bzcx cy cz

r K = hr a * + k

r b * + lr c *

T(r K ) = exp B11h

2 + B22k2 + B33l

2 + 2B12hk + 2B13hl + 2B23kl( )[ ]

c hexagonal

Uxx = Uyy ,

Uxy = 0

r a =a00

,

r b =

a / 23a / 20

,

r c =00c

r a * =1 / a1 / 3a0

,

r b * =

02 / 3a0

,

r c * =001 / c

r a * / a* =3 /21 / 20

,

r b * /b* =

010

,

r c * / c* =001

U11 U12 U13U12 U22 U23U13 U23 U33

=

3 / 2 1 / 2 00 1 00 0 1

Uxx 0 00 Uxx 00 0 Uzz

3 / 2 0 01 /2 1 00 0 1

=

3 /2 1 / 2 00 1 00 0 1

3Uxx / 2 0 0Uxx / 2 Uxx 00 0 Uzz

=

Uxx Uxx / 2 0Uxx / 2 Uxx 00 0 Uzz

a = 6.000

b = 5.000

c = 4.000

=120.0

=110.0,

=120.0

r a =ax00

r b =

bxby0

r c =c xcycz

123

200714