1 / 47

SAXS-WAXS (SWAXS) Small and Wide Angle X-ray Scattering Semra İde

SAXS-WAXS (SWAXS) Small and Wide Angle X-ray Scattering Semra İde Dept . of Physics Eng . , Hacettepe Univ . side@hacettepe.edu.tr. IAEA Regional Training Course , 8-12 November 2010. Nano structured materials. Monochromatic X-Rays. Scattered X-Rays. Multilayer Films,

irina
Télécharger la présentation

SAXS-WAXS (SWAXS) Small and Wide Angle X-ray Scattering Semra İde

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SAXS-WAXS (SWAXS) SmallandWideAngle X-ray Scattering Semra İde Dept. of PhysicsEng. , Hacettepe Univ. side@hacettepe.edu.tr IAEA Regional Training Course , 8-12 November 2010

  2. Nano structured materials Monochromatic X-Rays Scattered X-Rays Multilayer Films, Polycrystalline, Nanocomposites, Patterned structures, Bulk structures, Liquid crystals, Biological samples, Fractals, Gels, and etc. “When scientists have learned how to control the arrangment of matter at a very small scale, they will see materials take an enormously richer variety of properties” Richard Feynman (1959)

  3. 1013 photon/s/mm2 High flux, more intensed x-rays 108 photon/s/mm2 Widely used flux, conventional x-rays

  4. Differentformedaggregats can be investigated Lamellar Diluted -I Densed -I The other densed systems Diluted -II Densed -II

  5. 03.01 -20.07 2009

  6. SWAXS (Small and Wide Angle X-Ray Scattering) Analizleri Detection of Scattered x-rays I (Scattering intensity) -k k’ q 2ө WAXS X-ray source SAXS q (Å-1) Nano-structuredsample Detector I (Scattering intensity) q, X-ray scatteringvector q= k´-k |q|=2 k sin q= 4 sin /  q (Å-1) k SAXS (1-100 nm) WAXS (1-10 Å)

  7. A(q) = Ae (r) exp(-iq.r) dr Scattered wave amplitude (r) =  [A(q)/Ae] exp(iq.r) dq Radial electron density Fourier T. I(q)= |A(q)|2 = Ae2| (r) exp(-iq.r) dr |2 =  P(r) exp(-iq.r) dr Scattered wave intensity P(r) =  (u+r) (u) du =  I(q) exp(iq.r) dq Distance distribution function Fourier T. Real space Reciprocal space

  8. The followed process to determine structures is used Measuring data In addition to SAXS technique other techniques are: SANS ( Small angle neutron scattering) XAFS (X-ray Absorption Fine structure), XRD (X-ray Diff.) and Microscopy techniques. More sensitive and recordable structural results can be obtained by this combination . Determining of structural parameters R, M, V etc. Defining model structure in real space and for this purpose using other collaborative techniques Construction of the model in q space and fitting of the experimental and theoretical results

  9. 1. region 2. region 3. region

  10. I Experimental curve I(q) = N [F(q)]2 S(q) q P Particle Form Factor P(q)= F(q) 2 Solution Structure Factor S q q F(q)= 3V (1-2) [ sin(qR) – qR cos(qR) ] / (qR)3 I(q) = N [P(q)] Diluted identical I(q) = N1 [P1(q)]+ N2 [P2(q)] It defines the relatonship between the positions of the particles Dilute two type particles I(q) = N  g(R) [P(q)] dR Dilute polydisperse

  11. Calibration of the q-scale (WAXS) with p-Br-BA powder: WAXS sample: lactosepowder sample-detectordistance: 29.5 cm activelengthofdetector ~ 5 cm 1024 pixels 50 µm/pixel 2~18° 2~26° 3.2Å 4.8 Å

  12. SAXS Primary beam (attenuated) FWHM ~ 350 µm center of incident primary beam sample: Lupolen sample-detectordistance: 28 cm activelengthofdetector ~ 5 cm 1024 pixels 50 µm/pixel 2665 Å 800 Å 2~8° 11Å Calibration of the q-scale (SAXS) with Ag-behenate powder: Lamellar d-spacing: d = 58.38 Å

  13. Guinier region I ln I Guinier line I(q) =I(0) exp(-R2q2/3) tan  = -R2/3 1/R . q(nm-1) q2 Diluted systems-I Protein or polymer solutions, etc. First determined structural information - Radius of gyration, - Mass, volume and shape

  14. After the cryst. Before cystallization R<R0 R=R0 R<R0 Spherical nano crystals embeded SiO2 Noncrystallized aggregations Nanocrystals glass Different electron densities Nanocrystals

  15.  r 2 (r) d3r R2 =   (r) d3r ____________ R= (a2+b2+c2)/5 ____ R= (3/5) r = 0.77 r Radius of gyration Elipsoid a,b,c elipsoid axes Guinier law (q0) Sphere r, radius I(q)q4 Porod law (q) lim I(q) q4 = constant lim I(q)= 2 (1-2)2 S / q4 S, surface area Porod region q (Å-1)

  16. Q = V <2>  Fluctuation in the electron densities V Total volume causing the scattering Kratky plots Invariant I.q2 (nm) -2 Q Sample: Amorph and crystalline regions in the structure Two phase polymers Q = V (k-a)2 ak k , a electron densities of the phases a , k volume fractions of the phases q (nm) -1 Kratky plots with Porod law

  17. Lamellar Structures I q The positions of Bragg peaks for h = 1, 2, 3 give the lamellar distance (1/d) If we look through the perpendicular direction of the lamelar structure, we may define crystallographic order in SAXS range. In this case, by using scattering intensity ratios and peak positions, some scattering rules ( for hexagonal, cubic etc.) controlled and compaired to obtain the real phases.

  18. Some ordered cubic morphologies Im3m P-surface Pn3m D-surface Ia3d G-surface Figures, H. Amenitsch, SR School-ICTP

  19. Hegzagonal struct. Lamellar fluid ? I. III. II. lam hex

  20. PS-b-PEO Co-polymer phase transition Accordingtotheobserved q ratios (1) Periodicstructure： 1 : 2 : 3 : 4…; (2) Cubic： 1: 2 : 3 : 4 : 5 …. ; (3) Hegzagonal 1: 3 : 4 : 7 : 9 : 12

  21. Photonic crystals Interplanar distance is increasing with increasing temperature Heating Blue Light blue

  22. Spin-cap (rotating capillary) 300 s / Frame Sample rotation enhances signal-noise ratio SAXS 300 s / Frame 45 ° WAXS SWAXS scanning of phase transitions 20° www.hecus.at

  23. ln I(q) ln I(q) 0.05 0.05 0.05 0.10 0.10 0.10 0.15 0.15 0.15 q (Å-1) q (Å-1) ln I(q) ln I(q) Guinier Slope Porod q (Å-1) -2.50 -2.00 -1.50 -1.00 ln q

  24. Shapereconstruction

  25. A serial research on pH and temperature dependent-water soluble diblock copolymers [2-(dietilamino) etil metakrilat]-b-[2-(dimetilamino) etil metakrilat] (DEAn-b-DMAm) Hydrophillic(repulsion) Hydrophobic (attraction) shell core t= thicknes of the shell Rc = core radius Rs = t + Rc ρc = core electron density ρs = shell electtron density ρç = solution electron density pH controls charge level and if the misel size increase s, electrostatic repulsion becomes effective. t Rc ρc ρs Rs ρç Volume hight and base area of the cone were determined beside of packing parameter DEAn-b-DMAm diblock copoylmers are stable (n/m=1/2) in misellar forms at23C ve pH=7,7. size distributions are narrow and forms are spherical. For T=22,0-25,5C, pH=7,6-8,0 and n/m=0,25-0,73 values, misel numbers per unit volume, misel sizes, shell thickness, core radius and densities have been determined by SAXS analysis.

  26. 13 nm Y9,Y10 Y11, ……, Y20 Y9,Y10 Cubic structures occured by DNA and peptid connected spherical gold nanoparticles

  27. liquid paraffin, non-ionic surfactants (Brij 72 and Brij 721P) and/or pure water H3

  28. AFM View TEM View

  29. [D.I. Svergun, Biophysics J. 1999, 76, 2879-2886]

  30. Ferroelectric thin films, P.C. Mclntyre Res. Group, Stanford Photovoltaics, H. Kurz, Inst. of Semiconductor Elect. Germany Multilayered Al-Si Porous thin films, C. Orilall , Cornel Univ. Ultra-thin solid oxide fuel cell, F.B. Prinz ,RPL Stanford Engineering Nonhomogen dielect. (sculptured) thinfilm, STF, A. Lakhtakia, Penn State SrGa2S4:Ce thin-film, K. Tanaka, NHK Lab. Japan

  31. n+ Ga As Sample I (7) Sample II (8) 20 mol% 24 27 33 21 mol% 24 30 35 400 Å • Å 55 Å • 45 • 45 40 400 Å 400 Å n Ga As 400 Å i Al Ga As n+ Ga As GaAs , a= 5.65 Å,  = 5.32 g/cm3 AlGaAs, a= 5.66 Å,  = 3,76 g/cm3

  32. k is decay constant (interfacial area) for a two phase system. It depends on the total inner surface (S) and the mean-square electron density fluctuations dc dac da Q invariant Volume fractions It has the dimention of a resprocal volume Total irradiated volume

  33. Mean sizes of the planar aggregations in the content of the sample I and II are 198.09 and 121.67 Å , respectively.

  34. Summary Analysis of total scattering gives valuable insight in the structure-properties relationship High resolution instruments open the door to medium-range order investigations Usage of collaborative techniques always preferable to reach more detailed knowledge.

  35. Thank you for your attention

  36. GISAXS 0.2- 0.6 ⁰ 2. BP LS 1. BP SB PB + Düzgün yönelmiş tabakalar İzotropik lipozom af W- tarama ai www.hecus.at

  37. Lc SAXS ile algılanan nano-oluşumlar (1-100 nm) WAXS ile algılanan nano-oluşum iç yapıları ( 1-10 Å) SAXS ile elde edilen bilgiler: *Kesikli çizgilerle gösterilen elektron yoğunluk farklarının yüksek olduğu nano oluşumların şekli/şekilleri * Nano-oluşumların ortalama büyüklükleri *Nano-oluşumlar arası ortalama uzaklık ve uzaklık dağılımları *Birim hacimdeki nano-oluşum sayıları v.b. bilgiler. Lc : correlation distances Plaka formu için yapısal bilgiler İkili uzaklık dağılımları Polimer içine dağılarak bulundukları genel malzeme ortamının elektron yoğunluğunu artıran moleküler saçaklanmalar

  38. Bütün verinin GNOM programı ile arıtılması

More Related