Application of X-Ray Diffraction (XRD) Technique in Nano Composite Materials

8/3/2019 Application of X-Ray Diffraction (XRD) Technique in Nano Composite Materials

1/36


2/36

History of X-ray and XRD

Wilhelm Conrad Rntgen discoveredX-Rays in 1895.

1901 Nobel prize in Physics

Wilhelm Conrad Rntgen (1845-1923)

A modern radiograph of a handBertha Rntgens Hand 8 Nov, 1895


3/36


Radiographs like the ones in thelast slide are simplyshadowgrams.

The X-rays either pass straightthrough or are stopped by the

object. The diagram on the upperleft illustrates the principle andshows a perfect shadow.

In reality, a large fraction of theX-rays are not simply absorbedor transmitted by the object butare scattered. The diagram onthe bottom left illustrates thiseffect and illustrates the fuzzyedge of the object that isproduced in the image by thescattered X-rays.


4/36

Schematic for X-ray Diffraction

A continuous beam of X-rays isincident on the crystal

The diffracted radiation is veryintense in certain directions

These directionscorrespond to constructiveinterference from wavesreflected from the layers ofthe crystal

The diffraction pattern isdetected by photographic film


5/36

The first kind of scatter process to berecognised was discovered by Max vonLauewho was awarded the Nobel prize for physicsin 1914 "for his discovery of the diffraction ofX-rays by crystals". His collaborators WalterFriedrich and Paul Knipping took the picture

on the bottom left in 1912. It shows how abeam of X-rays is scattered into acharacteristic pattern by a crystal. In thiscase it is copper sulphate.

The X-ray diffraction pattern of a pure

substance is like a fingerprint of thesubstance. The powder diffraction method isthus ideally suited for characterization andidentification of polycrystalline phases.


Max von Laue (1897-1960)


6/36

Production of X-rays

X-rays are produced when high-speed electrons are suddenlyslowed down

Can be caused by theelectron striking a metaltarget

A current in the filament causeselectrons to be emitted

These freed electrons areaccelerated toward a dense

metal target The target is held at a higher

potential than the filament


7/36

Equipment

Bruker D8 Analytical X-ray Systems


8/36

Goniometer

2-Theta:Theta Setup


9/36

X-ray

spectrum


10/36

Braggs Law

The beam reflected from the lowersurface travels farther than theone reflected from the uppersurface

If the path difference equals someintegral multiple of the wavelength,constructive interference occurs

Braggs Lawgives the conditions

for constructive interference

2 d sin = m , m = 1, 2, 3


11/36

Problem: X-ray diffraction

X-rays of wavelength 0.140 nm are reflected from acertain crystal, and the first-order maximum occursat an angle of 14.4. What value does this give for

the interplanar spacing of this crystal?


12/36

Photo of X-ray Diffraction Pattern

The array of spots is called aLauepattern

The crystal structure isdetermined by analyzing thepositions and intensities of thevarious spots

This is for NaCl


13/36


14/36


15/36


16/36


17/36


18/36


19/36


20/36


21/36


22/36


23/36


24/36

Nano-Kompozitler


25/36

Nanoteknolojinin z, molekler boyutta alarak,

molekler yaps yenilenmi byk yaplar elde etmektir.Malzemelerin nanometrik boyuttaki zellikleri, aynmalzemenin makro boyuttaki zelliklerine gre deiiklikgstermektedir. Nano kompozitler, bir matris ierisinde

nanometre byklnde paracklarn dalmas ileoluan malzemelerdir.

Nano kompozitlerin malzemeye getirdii stnlkler;

modl arttrmas, glendirmesi, s direncini arttrmas,malzemeye gaz szmasn engellemesi, yanclnazaltmas olarak sralanabilir.

Nano-Kompozitler


26/36

NanoKompozitler

metal / seramik

seramik / seramik

metal / metal

polimer / seramik

inorganik/ polimer

polimer / polimer

NANO-KOMPOZTLER


27/36

1. Nanokompozitler seramik/seramik

Al2O3/(SiC, Si3N4, TiC, TiN, TiB2, BN), MgO/SiC,

Si3N4/(SiC, TiN, BN), Sialon/SiC, B4C/SiC, B4C/SiC/TiB2

2. Nanokompozitler seramik/metal

Al2O3/(W, Mo, Ti, Ni, Co, Fe, FeNi), ZrO2/(Mo, Ni. Co)

MgO/(Fe, Ni)

3. Nanokompozit temelli fonksiyonel seramiklerBaTiO3, ZnO, c-ZrO2 based nanocomposites

4. Nanokompozitler metal/seramicTi-Al Intermetalic based nanocomposites, MoSi2based nanocomposites

5. Nanokompozitler polimer/seramik ve polimer/metal

NANO-KOMPOZTLER


28/36

Toz

Mukavemet, tokluk, srnme, kimyasal kararllk,Yksek scaklk zellikleri

Mikroyap Makroyap

Arzu edilen zelliklereSahip KOMPOZT MALZEME


29/36

Nanoboyuttaki tozlar, gelimi zelliklere sahip nanokompozitleri

oluturmakzere seramik, metal ya da polimer gibi malzemeler iindedestekleyici olarak kullanlmaktadr.

Nano toz / Nano toz seramik kompozitler iin kullanlacak tozlar;

Yksek kimyasal saflk

Homojen toz boyut dalm Dk topaklama

Nano boyutta homojen olarak dalm tozlarn elde edilmesi gerekir.

BU NEDENLE TOZ RETM YNTEM NEML BR BASAMAKTIR.

NANO-KOMPOZTLER


30/36

DOLGU MADDELER


31/36

KL

Yksek iyon deiim kapasitesi

Yksek yzey alan/hacim oran,

Kolay ilenebilirlik, Dk maliyet

Polimerlerin termal, mekanik ve yanmazlk zelliklerini,kilin yap iinde kolay dalm ve kil tabakalarnnbirbirinden ayrlmasyla gelitirir.


32/36

MONTMORLLONT(MMT)


33/36

MONTMORLLONT(MMT)


34/36

3 tip yap olumaktadr: m

1. Mikro kompozit;Polimer kil tabakas arasnagiremez. Killer yn halindebulunur.

nm

2. Intercalated nanokompozit;Polimer zincirleri kil tabakalararasna yerlemitir.

3. Exfoliated nanokompozit;Kil tabakalar birbirindentamamen ayrlm ve polimermatriksine dalmtr.Polimer/nanokil etkileimimaksimumdur.

nm


35/36

Nanokompozit KarakterizasyonYntemleri

X In Krnm (XRD)

Taramal Elektron Mikroskopu (SEM)

Geirimli Elektron Mikroskopu (TEM) Taramal Sonda Mikroskobu (SPM)

Yakn Alan Taramal Optik Mikroskop


36/36

Application of X-Ray Diffraction (XRD) Technique in Nano Composite Materials

Documents

Transcript of Application of X-Ray Diffraction (XRD) Technique in Nano Composite Materials