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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
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7/31/2019 Phuong Phap Laue Ung Dung Va Doan Nhan Anh Nhieu Xa
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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
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7/31/2019 Phuong Phap Laue Ung Dung Va Doan Nhan Anh Nhieu Xa
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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
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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
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7/31/2019 Phuong Phap Laue Ung Dung Va Doan Nhan Anh Nhieu Xa
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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
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7/31/2019 Phuong Phap Laue Ung Dung Va Doan Nhan Anh Nhieu Xa
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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
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7/31/2019 Phuong Phap Laue Ung Dung Va Doan Nhan Anh Nhieu Xa
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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
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7/31/2019 Phuong Phap Laue Ung Dung Va Doan Nhan Anh Nhieu Xa
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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
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7/31/2019 Phuong Phap Laue Ung Dung Va Doan Nhan Anh Nhieu Xa
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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
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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
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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
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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
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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
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7/31/2019 Phuong Phap Laue Ung Dung Va Doan Nhan Anh Nhieu Xa
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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]
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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
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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:
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7/31/2019 Phuong Phap Laue Ung Dung Va Doan Nhan Anh Nhieu Xa
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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
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7/31/2019 Phuong Phap Laue Ung Dung Va Doan Nhan Anh Nhieu Xa
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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]
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7/31/2019 Phuong Phap Laue Ung Dung Va Doan Nhan Anh Nhieu Xa
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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.
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CM N THY V CC BN QUAN TM THEO DI
CM N THY V CC BN QUAN TM THEO DI
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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