phuong phap laue ung dung va doan nhan anh nhieu xa

7/31/2019 Phuong Phap Laue Ung Dung Va Doan Nhan Anh Nhieu Xa

1/21

TRNG I HC KHOA HC T NHIN

B MN VT L NG DNG

K THUT PHN TCH VT LIU RN

NG DNG CCH ON NHN&NG DNG CCH ON NHN

GVHD: GS.TS. L Khc Bnh

HVTH: Phan Trung Vnh


2/21

NI DUNG TRNH BY

IU KIN NHIU X BRAGG BIU DIN DIDNG HNH HC

1. XC NH S NH HNG CA TINH TH

2. XC NH S I XNG CA TINH TH

NI DUNG TRNH BY


3/21

iu kin c nhiu x:

d

2

2. .sin .d n

NH LUT BRAGGTrong :

NH LUT BRAGG

d: khong cchgia 2 mt mng songsongln cn2: gc hpbi tia X tiv tia nhiu x

: bc sng tia Xn: bcnhiu x

Tia X,

Biu din di dng hnh hc

CU EWALD

MNG OMi nt mng o Mt hmt mng v dhklmng thun

S0

MNG O

Mt im nt S0cchn lm gc.

Mt mt cu tm O,bn knh OS0 = 1/

S0O

CU EWALD

Chm tia X ti


4/21

S0

MNG O

S0

Chm tia X ti

CU EWALD Mi nt mng o Mt hmt mng v dhklmng thun

Gi s, c 1 nt mngo khc S0 nm trn

cu Ewald

Nt mng o nm

trn cu Ewald

P

I

Mt phngtrung trc (Q)

O

Gi (Q) l mt phngtrung trc ca S0P.(Q) S0P ti I.

2

0 02.S P S I

0 0.sinS I S O 1

d 1

1 12. .sin

d

2. .sind

iu kin nhiu x Bragg

iu kin nhiu x Bragg

Thay i bn knh cuEwaldThay i

S0

P

Nh vy, nhng nt mng ono nm trn cu Ewalds tha mniu kin Bragg, tc l cho vt nhiu x trn phim.

Thay i nh hngmng o Thay i

PHNG PHP LAUE

PHNG PHP LAUE PHNG PHP DEBYE

PHNG PHP DEBYE


5/21

Trn cu Ewald, c rt nhiu ntmng o tha mn iu kin Bragg.

S0

CU EWALD

P

O

Nhng nt ng phngl nhng nt thuc cng mt vngtinh th.

ng phng Cc nt mng o thuc cng mtvng to thnh mt ng trn

S0

P

S0

P

P

O

2

S0

T tm O, ni di cc nt ng

phng ct mn phim ti cc im

to thnh ng ellipse, y l

cc vt nhiu x trn phim.Mnph

im

S1

OS1P l mt nn trn xoayGc S P = 2

NHN XT

2< 90: ng cavt nhiu x ellipse

NHN XT


6/21

O2 = 90

0

Mnphim

2 = 90

0

: ng ca vtnhiu x ng parabol

O2 > 900

M

nphim

2 > 900

: ng ca vtnhiu x ng hyperbol

Vt nhiu x Laue camt tinh th Al (FCC)

2 < 900 2 > 900

ng ellipseng ellipse ng hyperbolng hyperbol

Phn tch cc vt nhiu x

S nh hng tinh th

S i xng ca tinh th


7/21

Xc nh s nh hng ca tinh thi vi tinh th lp phng: c bit

nh nhiu x Laue ctrc i xng bc 4

x

y

z

[100] x

y

z

[100]Phng [100] c nhhng // vi tia X ti

nh nhiu x Laue c

trc i xng bc 3

[111]

x

y

z

x

y

z

Phng [111] c nhhng // vi tia X ti

Tia XTia X


8/21

i vi tinh th bt k: Thc hin theo cc bc

Dng giy can in li ccvt nhiu x trn phim.

Xc nh vt ca tia ti S0(Vt ca tia ti c kch thc

ln nht v sng nht)

nh s cc vt nhiu x

S0

1

2

11

10

12

9

8

7

6

54

3

13

1514

1817

19

16

24

23

22

21 20o khong cch ligia S0

n vt nhiu x th i (i = 124)

Ngun tia Xa sc

Mu tinh th

Mnphim D

l15S0

2

S015 8

Gc nhiu x ng vi tng vt:

2

i

i

l

tg D

Vi D l khong cch t

mu tinh th n phim


9/21

Dng hnh chiu gnomo-stereo t nh nhiu x Laue:

t li Wulf di giy can,tm S0trng vi tm li Wulf.

S0

1

2

11

10

12

9

8

7

65

4

3

13

1514

1817

19

16

24

23

22

21 20

Li Wulf

dng hnh chiu ca 1 vt no (v d S1), quay giy can quanh S0n

khi S1nm trn ng xch o ca li.

S1

ng

xcho

T im Abn kia mpli, nhdu gc2trn

giy can

A

1800900

00

2 = 300

2


10/21

1800 00

2 = 300

2

Hnh chiu ca vt S1trn giy can

2

Ch chn ra nhng vt nhiu x m phnb trn cng 1 ng ellipse dng hnhchiu Gnomo-stereo.

Vt nhiu x nh Laue ca tm nhm mng

Hnh chiu Gnomo-stereo ca cc vt nhiu x


11/21

Nhng vt nhiu x nm trn ngellipse thuc cng 1 vng ca tinh th.

Nhng hnh chiu Gnomo-stereo ca ccvt nhiu x thuc cng 1 vng s lmt ng kinh tuyn ca li Wulf.

Xc nh trc vng v

gc gia hai trc vng

Xt cc vt

nhiu x caellipse nh.

A

B

on thng

AB i quatm li Wulf.

A

B

ng chiuGnomo-stereo


12/21

A

B

Quay on thng ABquanh tm li cho nkhi phng ca ABtrng ax

A

Ba

x

ng chiu Gromo-stereo ct ng quo ca li ti L. nhdu L.

ng chiuGnomo-stereo

ng xch o

T L, m hng v

trc ax mt gc 900

Ta c im K. Ly

L lm gc, dng vector LK.

Li Wulf c nh

L

L1800 900 0

0

A

Ba

x

K


13/21

Xoay on thng AB trli v tr ban u.

A

B

L

K

LK chnh l phng catrc vng tinh th cn tm.

nh vtnhiu

x Laue

ca tinh

th

Nh vy,trc vng ca cc vt nhiu x

trn ng ellipse nh chnh l vectorLK. Tng t cho ng ellipse ln.Gi s ta c vector EF.

L

K

EFGc (KL,EF) = Gc gia

2 trc vng

L1800 900 0

0

A

Ba

x

K


14/21

Xc nh trc vng vgc gia hai trc vng

Xc nh ch s ca trc vngS dng

GCGIAHAI

PH-NG

TINH

THTRO

-NG

HMNGLPPH

-NG

100 110 111 210 211100 00

900

110 450900

00

600 960

111 54,740 35,260900

0070,530

210 26,56063,430

900

18,43050,770

71,560

39,23075,040

00 36,870

53,130

66,42078,460 600

211 35,26065,900

310 54,740

73,220 61019,470

61,870 90024,09043,090

56,790

79,480 900

00 33,56048,190 600

70,500

80,400

BNG TRA

L

K

E F630

[210]

[100]


15/21

Xc nh s i xng ca tinh thT tnh i xng ca

cc vt nhiu x trn phim

nh nhiu x Laue phnb i xng tng ng

Ngun tia Xa sc

Mu tinh th

Mn phim

Dl15S0

2

S0

nh nhiu x Laue thngc tnh i xng qua tm S0

CHM TIA X

Trc i xngMt i xng

Song song

Tnh i xng ca tinh th

nh nhiux Lauec trc

i xng

bc 3

[111]

x

y

z

V D(100)

(001)

(010)

(100)

(001)(010)

Chiu tia X theo phng

zy

x

(001)

(100)

(001)(010)

1 1 1


16/21

x

y

z [001]

y

z[001]

x

y

z [001]

x

nh nhiu x Laue ctrc i xng bc 4

(111)

(111)

(1 11)

(1 11)

(111)

(1 11)

(111)

(1 11)

A

B

CD

E

(111) :

(111) :

(1 11) :

(1 11) :

ABC

AEC

ADB

ADE

Chiu chm tia X theophng [001], nh nhiux thu c c trc i

xng bc 4 tng ngvi tia X nhiu x trncc mt:


17/21

Tnh i

xng catinh th

Tnh i

xng ca

nh Laue

cao hn

nh Laue lun c tm i xng

nh Laue c th c 10kiu i xng khc nhau

Tinh th khngc trc i xng

no (hay trc bc 1)

nh Laue khngc tnh i xng

Lp 1

Tinh th c cc trci xng nm dc

theo tia X

nh Laue c trci xng bc 2, 3,

4, 6 nm phim

Lp 2, 3, 4, 6

Tinh th c mt phng ixng m cha phng tia X

nh Laue i xngqua ng thng phim

Lp m

Tinh th va

c trc ixng, vac mt i

xng

Lp 2m,3m, 4m,6m


18/21

Cc lp i xng Laue v c im i xng ca nh Lauevi hng tia ti dc theo cc trc khc nhau ca tinh th

Vi tinh th lp phng, phn bit lp m3 v m3m, cn chp thm 1 phim vi chmtia ti hng theo trc [111]


19/21

TI LIU THAM KHO

1. L Khc Bnh Bi ging Cao hc Vt l ng dng

hc phn K thut phn tch vt liu rn.

2. L Khc Bnh, Nguyn Nht Khanh Gio trnh Vt lCht rn, Nh xut bn i hc Quc gia, 2001.

3. L Cng Dng K thut phn tch cu trc bng tia

Rontgen, Nh xut bn Khoa hc v K thut, 1974.


20/21

CM N THY V CC BN QUAN TM THEO DI

CM N THY V CC BN QUAN TM THEO DI


21/21

Chng ti dch c mt s chngca mt s kha hc thuc chng trnhhc liu m ca hai trng i hc ni

ting th gii MIT v Yale. Chi tit xin xem ti: http://mientayvn.com/OCW/MIT/Vat_li.html http://mientayvn.com/OCW/YALE/Ki_thuat_y_sinh.html
http://mientayvn.com/OCW/MIT/Vat_li.htmlhttp://mientayvn.com/OCW/MIT/Vat_li.html

phuong phap laue ung dung va doan nhan anh nhieu xa

Documents