prof. dr. servet turan materials characterisation...

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MATERIALS

CHARACTERISATION

TECHNIQUES

(MLZ 222, 229 & 230)

Prof. Dr. Servet Turan

Thanks to Doç.Dr. Hilmi Yurdakul

Thanks to Tayfun Koçak &

Cem Eren Özbilgin

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PROBLEMS: OVERLAPPING ENERGIES

Anadolu University, Materials Science & Engineering, Eskisehir, Turkey

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BASICS OF WDS

Crystal change

motor

Crystal

X- ray

Spectrometer mounting interface

X-ray diffracted

Extrance slit

X-ray counter


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ROWLAND CIRCLE (WDX)


Specimen

Detector

Electron Beam Curved

Crystal

R

Rowland

Circle

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Wavelength dispersive spectroscopy (WDS)

WDS utilizes the wave properties of X-rays to discern emitted X-ray energies.

X-rays, like all wave energy, can be diffracted.

Some necessary background:

Diffraction of X-rays obeys Braggs law:

n=1, 2, 3, … , l=X-ray wavelength, d=the spacing between atomic planes in a

crystal, q=the diffraction angle

)sin(2 ql dn

q

incident X-rays in phasediffracted X-rays

out of phase

d

Suggested Curriculum Links

Physics: light diffraction, wave theory of matter


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Wavelength dispersive x-ray spectrometry (WDX)

EDX


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Wavelength dispersive x-ray spectrometry (WDX)

WDX


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COMPARISON OF EDX & WDX

WDX

EDX


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COMPARISON OF EDX-WDX


TaW

Ni

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COMMON CRYSTALS USED IN WDX


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WDX vs EDX

Advantages

(i) high peak/background ratio

(ii) easy to detect low atomic number elements

(iii) high peak resolution

Disadvantages

(i) very expensive

(ii) a need to use several crystals for entire spectrum

Therefore, time consuming

Numunenin kesinlikle düz olması gerekliliği


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Electron beam - sample interaction


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Electron beam - sample

interaction 2: Effect of kV


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interaction 2: Effect of atomic no.


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interaction 3

K

L


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CHEMICAL ANALYSIS (MICROANALYSIS)

Analysis performed on a very small part of a large

specimen

In principle, one can determine two things from the

x-ray spectrum emitted by any specimen:

(i) measurement of wavelength or energy of each

characteristic x-ray enables us to find out which

elements are present, i.e., qualitative analysis

(ii) measurement of how many x-rays of any type are

emitted per second should tell us how much of the

element is present, i.e., quantitative analysis

However, due to instrumental and specimen

requirements quantitative analysis is not easy


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EDS is a parallel collection

technique

All X-ray energies are collected

simultaneously and X-ray

spectrum of energy vs number

of counts produced.

From the energy of peaks the

elements present can be deduced

From the size of the peaks the

relative amounts of elements in

the sample can be estimated

Qualitative Analysis

C

Ca

O

Mg

P

P

Ca

Ca

0.5 1 1.5 2 2.5 3 3.5 4

Full Scale 3644 cts Cursor: 2.743 keV (71 cts) keVFull Scale 3644 cts Cursor: 2.743 keV (71 cts) keVFull Scale 3644 cts Cursor: 2.743 keV (71 cts) keV

Spectrum 1


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QUANTITATIVE ANALYSIS

Two questions to answer:

(i) What is the smallest amount of element X which

could be detected

(ii) What is the amount of an element in a specimen


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Ni 18.3%

O 25.9%

Si 2.2%Ti 8.1%

Fe 45.4%

Quantitative Results (weight%)


Ti

Ti

Fe

Fe

Ni

Ni

4 5 6 7 8

Full Scale 8635 cts Cursor: 6.023 keV (241 cts) keVFull Scale 8635 cts Cursor: 6.023 keV (241 cts) keVFull Scale 8635 cts Cursor: 6.023 keV (241 cts) keV

Mnpt1


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THE LIMIT OF DETECTABILITY

Should know minimum detectable concentration

(MDC)

If the count rate in the background is b counts per

second, if the counting time is t, then the background

level is bt and the smallest detectable peak is 2sqr(bt)

above the background.

What concentration of an element in the specimen

would give this peak. To answer this we must compare

our peak height with the peak height (P-B) given by a

standard specimen consisting of the pure element. MDC

is given by:


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Where p is the peak count rate on the pure element

standard. Simplifying this slightly we get:

To lower the MDC, reduce b, increase p and t. The

easiest is to increase the time of analysis.

EDX system have poorer peak-to-background ratios

than WDX,

Both systems have worse p/b ratios for the lighter

elements



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For the lighter elements, MDC is around 0.1% in EDX

and an order of magnitude lower for WDX.

The precise figure will depend on the atomic weight of

the trace element compared to that of the specimen

since the soft x-rays from a light element will be

strongly absorbed by a matrix of high atomic weight



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If one wants to quantify the relative amounts of different

elements present in a complex sample one has to account

for a number of factors and carry out a correction of the

data



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SPATIAL

RESOLUTION

DIFFERENT TYPES OF RESOLUTIONS!

5

Å

IMAGE

RESOLUTION

Anadolu Üniversitesi, Malzeme Bilimi ve Mühendisliği Bölümü

EYE

RESOLUTION

PEAK

RES.

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Sample

Preperation(Excl. SEM)

CHEMICAL

ANALYSIS

DEVELOPMENTS: 3 MAIN CONCEPTS!

5

Å

IMAGING


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WDS


Specimen

Scintillation

Counter


Crystal

R

Rowland

Circle

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EDS


Specimen

Detector

Electron Beam

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EBSD


Electron Beam

Back-scattered

Electron diffraction

Specimen

Detector

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EDS-WDS


Specimen


Crystal

R

Rowland

Circle

Detector

Scintillation

Counter

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XRF with WDS


Specimen

X-rays Curved

Crystal

Scintillation

Counter

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XRD


Target

Electron Beam Diffracting

Sample

Scintillation

Counter

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Kristal

Yapı

Üretim

Süreci

Özellik

Performans

Karak-ter-

izasyon

MALZEMELERİN KARAKTERİZASYONU NEDEN ÖNEMLİDİR?

Servet Turan, Anadolu Üniversitesi, Malzeme Bilimi ve Mühendisliği Bölümü, Eskişehir

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Faz

Analizi

Görüntü

Kimyasal

Analiz

Diğer


Karakter-izasyon

Teknikleri

Kalitativ

Kantitativ

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Nano

Piko

Mikro

Makro


60 karbon atomunun

sıralanmasıyla elde edilen

futbol topu şeklindeki

~1 nm çapında “fullerene”

molekülü, çelikten daha

güçlü, plastikten daha hafif,

elektrik ve ısıyı ileten

Uçucu kül~ 10-20 mm

Silikon atomlarıAtomlararası mesafe

0.078 nm

Karakter-izasyonun

Mertebeleri

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Elektron

Işık

İyon

Diğer


Mikroskoplar

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2D

3D

Dinamik


Elde EdilenBilgi Türleri

Atomik

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Karakterizasyonu halka nasıl anlatırız?


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WHAT?

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WHY?

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IS IT GOOD ENOUGH?

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HOW?

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WHAT DO I GET?

WHAT DO I DO?

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CHARACTERISATION TECHNIQUES

Non-Microscobic Tech.Microscobic Tech.

Light Microscopy

Scanning Electron Micr.

Transmission Electron Micr.

Other Tech.

Thermal Analysis

X-ray Diffraction

Spectroscopic Techniques

Other Tech.

Anadolu University, Materials Science & Engineering Department, Eskisehir, Turkey

MLZ 229MLZ 230

MLZ 222

https://www.facebook.com/groups/1657111924571465/

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WHAT IS THIS?


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WHAT IS THIS?

Energy (keV)

Inte

nsi

ty (

cps)


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nepheline syenite and 25% quartz

revealing quartz filler (Q), cuboidal

primary mullite (PM) and acicular

WHAT IS THIS?


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WHAT IS THIS?


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WHAT IS THIS?


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WHAT IS THIS?


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WHAT IS THIS?


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FATIGUE FRACTURED AIRCRAFT PART!


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WHAT IS THIS?


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5 Å

Yurdakul & Turan et al., Scripta Materialia, 65, 656 (2011)

WHAT IS THIS?


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MİKROYAPI NEDİR?

Anadolu Üniversitesi Malzeme Bilimi ve Mühendisliği Bölümü

Birim Hücre

Yer alan AtomArayer Atomu

Vida

Dislokasyonu

Taneler Arası

KırılmaTane İçi Kırılma

Tane Sınırı Fazı

TaneSınırı

Çökeltileri

Koherent

Çökeltiler

Koherent Olmayan

Çökeltiler

İkinci FazKayma

ÇizgileriKenar Dislo.

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MİKROYAPI NEDİR?


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PROBLEMLER


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PROBLEMLER-3D vs 2D

Numune

Mikroskop

Görüntü


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PROBLEMLER-3D vs 2D


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PROBLEMLER-3D vs 2D


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İnce Numune


NUMUNE KALINLIĞININ ETKİSİ

Kalın Numune

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Problem Çözen İlk Mikroskopçular !!!


It is a mammoth!

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ÖNERİLER

5 Å

-Si3N4 ‘de ve tane sınırlarında Ce!!


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Anadolu Üniversitesi, Malzeme Bilimi ve Mühendisliği Bölümü, Eskişehir

Görmeden İnanmam!

Gördüğüme de İnanmam!

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Phase rich in Zr

Görmeden İnanmam!

Gördüğüme de İnanmam!

Anadolu Üniversitesi, Malzeme Bilimi ve Mühendisliği Bölümü, Eskişehir

Kimyasal Analiz!

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Techniques

Properties

TG DTG DSC DTA STA

TG/DTA

Dilato-

meterXRD XRF MS FTIR

Atomic bonding

Qualitative elemental analysis

Quantitative elemental analysis

Qualitative phase analysis

Quantitative phase analysis

Crystallinity

Non-Crystallinity

Texture

Particle (or crystal) size

Particle shape

Crystal STructure

Bravais lattice

Lattice parameters

Elemental distribution

Phase distribution

Trace elements (less than 0.1 %)

Physical W….

Chemical W….

Phase Tran…… Te….

Dec…. Te….

Glass T… Te

Crys… Te….

For… Rea… Te

229 Final

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Techniques

Properties

TG DSC DTA STA

TG/DTA

Dilato-

meterXRD XRF LM SEM TEM EDS WDS SADP

Atomic bonding

Qualitative elemental analysis

Quantitative elemental analysis

Qualitative phase analysis

Quantitative phase analysis

Crystallinity

Non-Crystallinity

Texture

Particle (or crystal) size

Particle shape

Crystal STructure

Bravais lattice

Lattice parameters

Elemental distribution

Phase distribution

230 Final

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Techniques

Properties

TG DSC DTA STA

TG/DTA

Dilato-

meterXRD XRF LM SEM TEM EDS WDS SADP

Trace elements (less than 0.1

%)

Physical W….

Chemical W….

Phase Tran…… Te….

Dec…. Te….

Glass T… Te

Crys… Te….

For… Rea… Te

Me…… Te…..

Va… Te…

Powder sample

Bulk sample

Destructive

Non-Destructive

Please add a different

property

Please add a different

property

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What do I gain at the end of it ?

The student will be able to know how to characterise

any kind of sample


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Türk Elektron Mikroskopi Derneği (TEMD) üyeliğinin yanı sıra

European Microscopy Society (EMS), International Federation of

Societies for Microscopy (IFSM) ve International Federation of

Societies for Histochemistry and Cytochemistry (IFSHC) üyesi olma

ayrıcalığı kazanacaksınız. Bu sayede bu derneklerin vermiş olduğu

desteklerden faydalanabileceksiniz.

ÜYE OLMANIN AVANTAJLARI NELERDİR?

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prof. dr. servet turan materials characterisation...

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