10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST [email protected] MS213...
-
Upload
kelley-flowers -
Category
Documents
-
view
219 -
download
1
Transcript of 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST [email protected] MS213...
![Page 1: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/1.jpg)
X-ray diffraction
10/16/2014
Soon Ho KwonComputational Materials Science lab. [email protected]
MS213 Crystallography and Diffraction
![Page 2: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/2.jpg)
X-ray
X-Rays are part of the spectrum of electromagnetic radiation occupying the region between the ultraviolet and gamma rays.
The wavelengths of X-radiation commonly used for x-ray diffraction lie between 0.7 and 2.3 Å. Cu Kα is 1.54Å.
![Page 3: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/3.jpg)
X-ray
A high voltage power source is connected across cathode and anode to accelerate the electrons.
The X-ray spectrum depends on the anode material and the accelerating voltage.
![Page 4: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/4.jpg)
X-ray
Continuous X-ray Characteristic X-ray
![Page 5: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/5.jpg)
X-ray
![Page 6: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/6.jpg)
< Cu X-ray spectrum >
< (a) before and (b) after passage though a Ni-filter >
Filter for characteristic X-ray
![Page 7: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/7.jpg)
Bragg’s law
nλ=2dsinθ : Bragg’s Law
CB+BD=dsinθ + dsinθ = 2dsinθ
![Page 8: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/8.jpg)
Interference of Waves
![Page 9: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/9.jpg)
Basic Features of Typical XRD Experiment
![Page 10: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/10.jpg)
Detection of Diffracted X-rays
![Page 11: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/11.jpg)
A Modern Automated X-ray Diffractometer
![Page 12: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/12.jpg)
General mode Angle of X-ray and sample = θ
Angle of X-ray and detector = 2 θ diffraction only planes parallel to sample surface Preferred orientation
<Single crystal> <Poly crystal>
θ/2θ scan (coupled mode)
![Page 13: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/13.jpg)
Angle of X-ray and sample = α fixed (constant, 2~3o), Angle of X-ray and detector = 2 θ increase the X-ray dose rate in sample surface protect the detector from strong peak from substrate No preferred orientation
θ fixed, 2θ scan (glancing XRD)
<θ/2θ mode> <2θ mode>
![Page 14: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/14.jpg)
Angle of X-ray and sample = θ Angle of X-ray and detector = 2θ fixed
Orientation of sample Crystallinity is better as FWHM(full width at half maximum) is
smaller.
2θ fixed, θ scan (rocking curve)
Cu KαCu Kα + Cu Kβ
![Page 15: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/15.jpg)
Fundamentally, similar method to θ/2θ mode Angle of X-ray and sample = θ
Angle of X-ray and detector = θ Applicable for powder, liquid sample
θ/θ scan
![Page 16: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/16.jpg)
D-spacings and lattice parameters
![Page 17: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/17.jpg)
JCPDF card
![Page 18: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/18.jpg)
XRD Pattern of NaCl Powder
![Page 19: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/19.jpg)
Nondestructive method
Easily getting lattice parameter
Determination of small crystallite size
Easy to operate
Qualitative analysis
Quantitative analysis
Phase, crystallinity, preferred orientation
Merits of XRD measurement
![Page 20: 10 /16/2014 Soon Ho Kwon Computational Materials Science lab. KAIST honest@kaist.ac.kr MS213 Crystallography and Diffraction.](https://reader030.fdocuments.in/reader030/viewer/2022020208/56649d045503460f949d78bd/html5/thumbnails/20.jpg)
일정 실험 / 실습 내용 장소 구분
1 주(9 월 4 일 )
실습 소개 및 조 편성 응용공학동 (W1) 2427 호 단체
2 주(9 월 11 일 )
결정구조 모형 (BCC, FCC) 응용공학동 (W1) 2427 호 단체
3 주(9 월 18 일 )
결정구조 모형 (HCP, Diamond Cubic) 응용공학동 (W1) 2427 호 단체
4 주(9 월 25 일 )
결정구조의 이해 및 회절 응용공학동 (W1) 2427 호 단체
5 주(10 월 2 일 )
결정구조의 이해 및 회절 응용공학동 (W1) 2427 호 단체
6 주(10 월 9 일 )
한글날
7 주(10 월 16
일 )예비 응용공학동 (W1)
2427 호 단체
8 주(10 월 23
일 )중 간 고 사 응용공학동 (W1)
2427 호
9 주(10 월 30
일 )TEM 의 소개 및 실습 KARA 조별 (A)
10 주(11 월 6 일 )
TEM 의 소개 및 실습 KARA 조별 (B)
11 주(11 월 13
일 )X-ray diffractometer 의 소개 응용공학동 (W1)
2427 호 단체
12 주(11 월 20
일 )X- 선 회절 분석 KARA 조별 (A)
13 주(11 월 27
일 )X- 선 회절 분석 KARA 조별 (B)
14 주(12 월 4 일 )
고분해능 / Pole-figure X- 선 회절 분석 응용공학동 (W1) 2427 호 단체
15 주(12 월 11
일 )예비 응용공학동 (W1)
2427 호 단체
16 주(12 월 18
일 )기말고사 응용공학동 (W1)
2427 호
Schedule