Basics of XRD part IV - PDF Free Download

Basics of XRD part IV Dr. Peter G. Weidler Institute of Functional Interfaces IFG 1 10/31/17 KIT The Research University in the Helmholtz Association Name of Institute, Faculty, Department www.kit.edu

Overview Instrumentation X-ray source Slits,... Detectors Measurement Data evaluation positions, phase identification lattice parameters quantitative XRD - 2 - November 2017

crystallite and scattered x-ray: powder trace of detector circle - 3 - November 2017

X-ray tube - 4 - November 2017

selection of wavelength high absorption fluorescence --> Fe-bearing minerals (edge at 7.1keV (K β ) --> Cu K α at 8.0 kev --> λ = 1.24/keV --> 0.155 nm http://uahost.uantwerpen.be/mitac4/gr_tomo.html - 5 - November 2017

fluorescence Elements which fluoresce with Cu, Co or Cr radiation - 6 - November 2017

increased background - 7 - November 2017

Focusing elements: slits Soller slit Soller slit - 8 - November 2017

slit setting and illuminated area Slits [mm ] 0.1 0.2 0.4 1 Slits [ ] 0.05 0.1 0.2 0.5 2θ = 2 10 20 40 100 2θ = 4 5 10 20 50 2θ = 6 3 7 13 33 2θ = 8 3 5 10 25 2θ = 10 2 4 8 20 2θ = 12 2 3 7 17 2θ = 20 1 2 4 10 2θ = 30 1 1 3 7 2θ = 60 0 1 1 3 2θ = 90 0 0 1 2 goniometer radius = 200. L = R * tan(α) / sin(θ) L irradiated sample length [cm] R diffractometer radius [cm] α angular opening of slit variable slit - 9 - November 2017

Focusing elements: mirrors bend single crystal with defined face beam widening sample with irregular shape monochromatic beam removal of K β -part + line shape - intensity (70% loss) - 10 - November 2017

Focusing elements: monochromator Quartz (101) 1 divergence slit 0.15 receiving slit with... after: http://xrd-cmmp.blogspot.de/search/label/monochromator - 11 - November 2017

sample position detector X-ray tube horizontal 9-fold......and 100 + X fold... transmission capillary tube - 12 - November 2017

detectors solid-state single channel counter time saving! scan 2-122 2θ, 0.010 2θ, 5 sec per step: SCC: LynxEye : 16 hrs 40' 0'' 5' 13'' 192-stripe counter - 13 - November 2017

accessories heating stages for temperatures from below 0 C up to over 2000 C in-situ measurements in different atmospheres (air, N 2, He, CO 2 etc...)... and much more different set-ups, e.g. grazing incident, reflectometry... more examples and explanations: http://xrd-cmmp.blogspot.com/ - 14 - November 2017

Measurement What is important? Is XRD the right method for your problem?!?!?!? If YES --> sample material: e.g. stable at air, dry, moist etc.. amount available --> what do you want to know from the sample? --> composition or type of material (single phase) what is it? --> lattice parameters --> e.g. substitutions --> composition (mixture) how much of what? IF convincing answers --> THEN measurement parameters - 15 - November 2017

Measurement parameters 4 important measurement parameters: start end step width counting time per step --> measurement time compromise between measurement time and number of samples = total time and availability of XRD machine... but do not forget: grabby data, grabby results - 16 - November 2017

data evaluation - peak position Hematite 2700 2600 2500 2400 2300 2200 2100 2000 1900 1800 1700 d=2,69 hand-picking of peak positions, or... Lin (Counts) 1600 1500 1400 1300 1200 d=2,51 1100 1000 d=1,69 900 800 d=3,68 d=1,84 700 600 500 d=2,20 400 300 200 100 0 21 30 40 50 60 70 80 2-Theta - Scale spheric hematite aggregate - File: hem_sphere.raw - Type: 2Th/Th locked - Start: 2.000 - End: 82.000 - Step: 0.025 - Step time: 20. s - Temp.: 25 C (Room) - Time Started: 17 s - 2-Theta: 2.000 - Theta: 1.000 - Phi: 0.00... automatic peak picking - 18 - November 2017

data evaluation - phase identification Angle d value Intensity Intensity % 2-Theta Å Count 24,202 3,67 718 25,6 33,202 2,70 2808 100,0 35,685 2,51 1568 55,8 39,316 2,29 102 3,6 40,921 2,20 496 17,7 43,585 2,07 54,0 1,9 49,517 1,84 701 25,0 54,082 1,69 954 34,0 57,588 1,60 237 8,4 62,452 1,49 509 18,1 64,035 1,45 505 18,0 68,391 1,37 23,0 0,8 69,576 1,35 64,0 2,3 71,918 1,31 265 9,4 72,150 1,31 174 6,2 74,833 1,27 22,0 0,8 75,486 1,26 122 4,3 77,762 1,23 59,0 2,1 77,953 1,22 48,0 1,7 78,818 1,21 32,0 1,1 79,976 1,20 29,0 1,0 80,727 1,19 86,0 3,1 identify peaks positions with positions of known materials... - 19 - November 2017

data evaluation - automatic search - 20 - November 2017

data evaluation Hematite 2700 2600 2500 2400 2300 2200 2100 2000 1900 1800 1700 Lin (Counts) 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 21 30 40 50 60 70 80 2-Theta - Scale spheric hematite aggregate - File: hem_sphere.raw - Type: 2Th/Th locked - Start: 2.000 - End: 82.000 - Step: 0.025 - Step time: 20. s - Temp.: 25 C (Room) - Time Started: 17 s - 2-Theta: 2.000 - Theta: 1.000 - Phi: 0.00 01-087-1164 (C) - Hematite - Fe2O3 - Y: 81.73 % - d x by: 1. - WL: 1.54056 - Rhombo.H.axes - a 5.03530 - b 5.03530 - c 13.74950 - alpha 90.000 - beta 90.000 - gamma 120.000 - Primitive - R-3c (167) - 6-301.904 - I/Ic PDF - 21 - November 2017

quantitative work 4000 top soil; dust particles 3000 Lin (Counts) 2000 1000 0 3 10 20 30 40 2-Theta - Scale ED sample M2 - File: ED_M2.raw - Type: Locked Coupled - Start: 3.000 - End: 82.000 - Step: 0.009 - Step time: 160.2 s - Temp.: 25 C - Time Started: 14 s - 2-Theta: 3.000 - Theta: 1.500 - Chi: 0.00 - Phi: 0.00 - X: 0. - 22 - November 2017

quantitative work - data bank 4000 top soil; dust particles 3000 Lin (Counts) 2000 1000 0 3 10 20 30 40 ED sample M2 - File: ED_M2.raw - Type: Locked Coupled - Start: 3.000 - End: 82.000 - Step: 0.009 - Ste 01-086-1560 (C) - Quartz low - SiO2 - Y: 27.34 % - d x by: 1. - WL: 1.5406 - Hexagonal - a 4.91600 - b 4.9160 01-086-2339 (C) - Calcite - Ca(CO3) - Y: 12.50 % - d x by: 1. - WL: 1.5406 - Rhombo.H.axes - a 4.98400 - b 4 01-089-6538 (C) - Kaolinite - Al2(Si2O5)(OH)4 - Y: 11.64 % - d x by: 1. - WL: 1.5406 - Triclinic - a 5.15400 - b 01-086-1385 (C) - Muscovite 2M1 - K0.86Al1.94(Al0.965Si2.895O10)((OH)1.744F0.256) - Y: 9.39 % - d x by: 01-089-0598 (C) - Hematite, syn - Fe2O3 - Y: 3.13 % - d x by: 1. - WL: 1.5406 - Rhombo.H.axes - a 5.03800-01-077-0982 (C) - Sanidine - K0.42Na0.58Ca0.03AlSi3O8 - Y: 2.35 % - d x by: 1. - WL: 1.5406 - Monoclinic - 01-085-1045 (C) - Chabazite, syn - H3.1Ca0.25Al3.60Si8.40O24 - Y: 5.47 % - d x by: 1. - WL: 1.5406 - Rhom 2-Theta - Scale 00-033-0018 (I) - Gibbsite, syn - Al(OH)3 - Y: 3.13 % - d x by: 1. - WL: 1.5406 - Monoclinic - a 8.65520 - b 5.0-23 - November 2017

quantitative work - additives addition of -- standard material -- same material mixtures: absorption coefficient of additive close to samples example: top soil / dust particles how much quartz is present? addition of known amounts of quartz to sample XRD at exactly the same conditions - 24 - November 2017

quantitative work - additives intensity of phase a I a = K a X a / ρ a (μ/ρ) matrix with (μ/ρ) matrix mass absorption coefficient K a set-up constant X a rel. amount of phase a <--> CuKα 11% reduction in 10cm air!! addition of standard or same material I a / I std = (C a K a )/ (ρ a (μ/ρ) matrix )/( C std K std )/ (ρ std (μ/ρ) matrix ) I a / I std = (C a / C std ) K' with K' = (K a ρ std ) / (K std ρ a ) C a = (I a C std ) / ( I std K' ) = concentration of interesting material I a measured C std known I std measured K' calculated with standard... - 25 - November 2017

quantitative work - K' determination 11000 10000 9000 8000 7000 Lin (Counts) 6000 5000 4000 3000 2000 1000 0 11.64 11.7 11.8 11.9 12.0 12.1 12.2 12.3 12.4 12.5 12.6 12.7 12.8 12.9 13.0 13.1 2-Theta - Scale - 26 - November 2017

quantitative work addition of -- standard material -- same material satellite peaks!! avoid peak overlap <--> intensity determination check for particles orientation effects Lin (Counts) 4000 3900 3800 3700 3600 3500 3400 3300 3200 3100 3000 2900 2800 2700 2600 2500 2400 2300 2200 2100 2000 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 top soil; dust particles top soil; dust particles Lin (Counts) 5000 4000 3000 2000 1000 0 17.1 18 19 20 21 22 23 24 25 26 27 28 29 30 31 6.4 7 8 9 10 11 12 13 14 15 16 2-Theta - Scale 2-Theta - Scale - 27 - November 2017

quantitative work more advanced and appropriate techniques: --> Lev S. Zevin & Giora Kimmel Quantitative X-ray Diffractometry Springer 1995 372pp. more possibilities --> Rietveld Method - 28 - November 2017

quantitative work Rietveld method: whole pattern approach what does it need: 1. space group 2. lattice parameter 3. fractional coordinates } structure file... good data - 29 - November 2017

quantitative work Lin (Counts) 12000 11000 10000 9000 8000 7000 6000 5000 4000 3000 Example: estimation from with peak height fit 4 oxides Result: XRD XRF Corundum 11.8 20.9 Fluorite 11.9 22.1 Zincite 55.6 19.5 Brucite 20.7 36.1 Zincite too high and underestimation of Brucite --> preferred orientation!! 2000 1000 0 14 20 30 40 50 60 70 80 90 100 2-Theta - Scale File: CPD-2.RAW - Type: 2Th/Th locked - Start: 5.000 - End: 150.000 - Step: 0.020 - Step time: 3. s - Temp.: 25 C (Room) - Time Started: 0 s - 2-Theta: 5.000 - Theta: 2.500 - Aux1: 0.0 - Aux2: 0.0 - Aux3: 0.0 - Display p 00-046-1212 (*) - Corundum, syn - Al2O3 - Y: 8.92 % - d x by: 1. - WL: 1.5406 - Rhombo.H.axes - a 4.75870 - b 4.75870 - c 12.99290 - alpha 90.000 - beta 90.000 - gamma 120.000 - Primitive - R-3c (167) - 6-254.808 - I/Ic P 01-089-4794 (C) - Fluorite - CaF2 - Y: 34.38 % - d x by: 1. - WL: 1.5406 - Cubic - a 5.46250 - b 5.46250 - c 5.46250 - alpha 90.000 - beta 90.000 - gamma 90.000 - Face-centered - Fm-3m (225) - 4-162.995 - I/Ic PDF 3.8 - S-Q 00-036-1451 (*) - Zincite, syn - ZnO - Y: 41.94 % - d x by: 1. - WL: 1.5406 - Hexagonal - a 3.24982 - b 3.24982 - c 5.20661 - alpha 90.000 - beta 90.000 - gamma 120.000 - Primitive - P63mc (186) - 2-47.6216 - I/Ic PDF 1. - S- 00-007-0239 (I) - Brucite, syn - Mg(OH)2 - Y: 25.01 % - d x by: 1. - WL: 1.5406 - Hexagonal - a 3.14700 - b 3.14700 - c 4.76900 - alpha 90.000 - beta 90.000 - gamma 120.000 - Primitive - P-3m1 (164) - 1-40.9027 - I/Ic PDF 1. - 30 - November 2017

quantitative work Rietveld approach: with PO for Brucite GOF 1.35 R exp 8.56 R wp 11.57 Result: XRF XRD Δ Corundum 20.9 21.6 +0.7 Fluorite 22.1 22.0-0.1 Zincite 19.5 19.4-0.1 Brucite 36.1 37.1 +1.0-31 - November 2017

but getting to Rietveld, it needs the basics for Rietveld... next lecture... - 32 - November 2017

Literature F. Donald Bloss Crystallography and Crystal Chemistry Mineralogical Society of America, 1994, pp.545 50-120 100-275BRL D.L. Bish & J.E. Post (Eds) Modern Powder Diffraction Reviews in Mineralogy Vol 20 Mineralogical Society of America, 1989, pp.369 30 70BRL H.P. Klug & L.E. Alexander X-ray Diffraction Procedures Wiley, 1954, pp.716 (second hand bookstores 8-300 20-700BRL) B.E. Warren X-ray Diffraction Dover Publications, 1969, 1990, pp.381 12 28BRL D.M. Moore &R.C. Reynolds X-ray Diffraction and the Identification and Analysis of Clay Minerals Oxford University Press, 1997, pp.378 50-60 100-140BRL - 33 - November 2017

Acknowledgment Bruker AXS Germany, Knielingen CEFET UMFG INCT-Acqua - 34 - November 2017