《固体物理学》课程教学课件（PPT讲稿）Chapter 2 Wave Diffraction & the Reciprocal Lattice 2.6 X-Ray Diffraction Methods 2.7 Applications of XRD

2.6 X-Ray Diffraction Methods Method Laue Rotating Crystal Powder Orientation Lattice constant Lattice Parameters Single Crystal Single Crystal Polycrystal (powdered) Polychromatic Beam Monochromatic Beam Monochromatic Beam Fixed Angle Variable angle Variable angle

2.6 X-Ray Diffraction Methods Method Laue Rotating Crystal Powder Orientation Single Crystal Polychromatic Beam Fixed Angle Lattice constant Single Crystal Monochromatic Beam Variable Angle Lattice Parameters Polycrystal (powdered) Monochromatic Beam Variable Angle

Crystal diffraction experimental methods a)Laue method:continuous X ray for a single crystal Sample X-ray source Collimator Forward Back ditfraction reflection plate plate position position Goniometer mount

Crystal diffraction experimental methods a) Laue method: continuous X ray for a single crystal

FeS2:two crystal phases 0 1( Figure 1-38 Laue X-ray diffractionspotpatternsfor(100)and(110)orientations with respect to pyrite (FeS)single crystals.(Photos courtesy of L.E.Murr,Oregon Graduate Center.)

FeS2 : two crystal phases

Laue Patterns The symmetry of the Laue spot pattern reflects the symmetry of the crystal when viewed along the direction of the incident beam. Laue method is often used to determine the orientation of single crystals by illuminating the crystal with a continous spectrum of X-Rays. Single crystals Continous spectrum ofX-Rays Symmetry orientation ofcrystals

• The symmetry of the Laue spot pattern reflects the symmetry of the crystal when viewed along the direction of the incident beam. Laue method is often used to determine the orientation of single crystals by illuminating the crystal with a continous spectrum of X-Rays. Single crystals Continous spectrum of X-Rays Symmetry & orientation of crystals Laue Patterns

b)Debye-Scherrer method Constant wavelength for powders X ray tube Diffraction cone Collimator Powder sample Useful for samples that are difficult to obtain in single crystal form.The powder method is used to determine the lattice parameters accurately a,b and c

b) Debye-Scherrer method Constant wavelength for powders Useful for samples that are difficult to obtain in single crystal form.The powder method is used to determine the lattice parameters accurately a, b and c

Photograph of a XRD Diffractometer (Courtesy H&MServices.)

Photograph of a XRD Diffractometer (Courtesy H&M Services.)

Powder XRD patterns h [t.Lu.] Old diffraction pattern (220) 500 311) 65 250 070 (400) 080° 60 计数器位置.20（度） Diffractometer pattern

Powder XRD patterns Old diffraction pattern Diffractometer pattern

Phase analysis for Powder diffaction JCPDS-Joint Committee on Powder Diffraction Standards ICDD-International Centre for Diffraction Data 一、PDF-Powder Diffraction File Index:Alphabetical Hanawalt by the 3 strongest diffraction lines Fink by the values of d 二、PCPDFWIN

卡片序号 数据的可信度：星号， 23-22 三条最强线及第 一条线d值和强度 化学式 i,O,空白，C,R 及名称 5,22 4.52 4.59 5.29 NH 103 实验方法能测 曲出塑米 相恤 到的最大d值 衍射强度的 直 样品最强线与刚玉最强 抢测方式 线强度比(50/50) Rad.Cy d A 1.54 参考文献 0. Dis. ✉A1/11bkl -d-A bkI Cut off- fractonetor 作： 5.26 1 110 2.019 8 10J Ref。 a/b和 -tandards, 空碰 020 1.971 115 晶胞参数 单胞化学 理论 90 101 1.862 042 1 1.854 4 321 Orthorho S.G.Pe2jr 式量数 密度 100 c06.3811Ay 1.48 20 6,095 60 9.1706 oCU.0938 3.190 35 1,3428 1 Rd. D3.417 Ibid. 光学数据 3.013 8 1.7394 1.865 2.760 1.6857 1.6097 10 日uB e1,785 Sim+】 2.732 211 1.6022 4 a 2V large D 1.5949 cp Color Coloriess 2.626 14 220 3 Ref.Ibid. 2.618 11 022 1.5283 2.533 131 1.5181 37 he sample.Mh3 prepared by evaporating事ture of the申 2.427 1 221,122 1.5150 % 145 solutions of NHLOH and'HIO3. 2.292 14 040 1.5072 7 303,024 attern at 25.Internal standard:W. 2.260 20 202 1.4872 313 At 8s"C thee is a fidst order transition to a non- 2,206 2 032 1.4479 161 olar phase, 2.088 1J2 1.4318 323,402 143.0(0.0137,51). 2.046 8 141 1.4281 6 204 See following card 2.027 2 222.301 1.4115 214

PDF 230022,Wavelength 1.54056 (A) 23-0022 Oualitu: NH4103 CAS Number Ammonium lodate Molecular Weight:192.94 Ref:Natl Bur.Stand.[U.S.]Monogr.25,10,7[1972] Volume[CD]:375.07 Dx3.417 Dm Sys:Orthorhombic Lattice:Primitive S.G.:Pe21n (33] 圣e Cell Parameters: a6.409b9.170 c6.381 SSF0M:F30=43[.0137.511 59 3.0 d ( /lcor:4.80 Rad:CuKal d(A) Int-f d(A] Int-f d(A] Int-f h .ambda:1.54056 5.2600 1 1 10 20270 得 21 201 1.4281 6 0 4.5860 65 0 2.0190 .4115 d-sp: 4.5230 1 0 1 1.9710 <1 1 1.3914 4.0570 3 1 1 1 1.8620 0 23321 1.3794 3.2200 10 1 2 1 1.8540 8 1 3665 3.1900 30130 0 22 ,8480 1 3638 1.7428 3521 3341 2.8650 1 1 1.7394 3132 323 1.3135 27600 3 0 16857 <1 3 1.3094 21 27320 2 8 220 1 16097 1 ,2660 0 6022 4221134006 2596 11 21 .5949 2570 2.5330 1 .5283 2400 2040 1 .2187 1 20 22324 1 .5181 43370 3 5150 44016 13331 121 3324664 223242340335145104 15622344140642280 20 7 4400243044313215041 20 033 222 1.5072 1.4872 71 20880 1 4479 1 6 331 1.1303 1 2.0460 18 1 4 1 1.4318 8 0 2 1.1112 1 1