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8/8/2019 TISCO XRD-2

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The electromagnetic Spectrum

Electric and magnetic fieldassociated with a wavemoving in x direction

Variation of E, (a) with t at fixed value ofxand (b)with x at a fixed value oft


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X ray spectrum of molybdenum asa function of applied voltage

Spectrum of Mo At 35 kVandResolved K doublet

Mosley relation between and Zfor two characteristic lines Electronic transition in an atom


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Variation with WK per xray quantum

Experimental arrangement formeasuring the absorption

Atomic energy level

Relationbetween theV applied to

an x-raytube andthe short

wavelengthlimit of thecontinuous

spectrum

Comparison of spectra ofcopper radiation


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Cross section of sealed-off filament x-ray tube

Wiring diagram of self-rectifying filament tube


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A point lattice

A unit cell


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The fourteen bravais lattices


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Incises of directions Plane designation by MillerIndices

Miller indices of latticeplane

(a) Miller indices of hexagonal unit

cells lattice planeb indices of lane and direction

All shaded plane in cubic latticeshown are plane of zone [001]


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The structure of (a) CsCl (common to

CsBr, NiAl, ordered -brass, orderedCuPd tec.) and (b) NaCl (common to

KCl, CaSe, PbTe, etc.


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Effect of path difference on relative phase Diffraction of x-ray by a crystal

Equivalence of (a) A second-order 100 reflectionand (b) a first-order 200 reflection


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Debye-scherrerpowder method

(a)relation of film tospecimen andincident beam;

(b) (b) appearance of

film when laid outflat

Debey scherrerpowder pattern of

copper (FCC),tungsten (BCC) andzinc (HCP).

Filtered copperradiation

camera diameter=5.37 cm


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Effect of crystal size on diffraction

Effect of particles size ondiffraction curves


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(a) Scattering by an atom

(b) Diffraction by a crystal

Comparative x-ray scatteringby crystalline

solids

amorphous solid

liquid and mono-atomic gases


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(a) Base-centered, and(b) body-centeredorthorhombic unit cells

Diffraction from (001)planes of (a) base-

centered and (b) body-centered orthorhombic

lattices

Coherent scattering of x-rays from a single electron


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X-ray scattering by an atom

Atomic scattering factor of copper


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Effect of atom position on phasedifferences between diffracted rays

Three dimensional analogueof phase difference


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Addition of sine waves of different phase and amplitude

Vector addition of waves A wave vector in the complex plane


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Calculated diffraction patterns for various lattices s = h2 + k2 + l2


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Partial Hull-Davey chart for simple tetragonal lattices


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Effects of cell

distortion onpowderpatters. Notethat change inlattice

parameterschangesBravais lattice.Linesunchanged inposition areconnected bydashed lines


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Variation of sinU with U. Error insinU due to error in U decreasesas U increases ((U exaggerated)

Relevant angles and lengths inback reflection region of Debye-

Scherrer camera


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Extrapolation of measuredlattice parameters againstsin2U (or cos2U)

Effect of specimendisplacement online positions

Extreme forms of extrapolation(schematic) (a) large

systematic errors, smallrandom errors: (b) smallsystematic errors, largerandom errors


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Plane diagrams showing

(a)partial solid solubility

(b) partial solid solubility

together with the formation ofan intermediate phase.

Plane diagrams and latticeconstant of a hypotheticalalloy system.


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Variation of martensite andaustenite lattice parameteswith carbon content.

Lattice parameters of somecontinuous solid solutions.Dot-dash lines indicate

Vegards law.


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Parametersmethod of

determining asolvus curve

Solvus curvedetermination in the

copper antimony system

by the parametric method(a) parameters versus

composition curve

(b) solubility versustemperature curve


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Unit cells of the disordered andordered forms of AuCu3

Atom arrangement on a (100) plane,disordered and ordered AuCu3

Phase diagram of thecopper gold system


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Powder patterns of AuCu3 (verycoarse grained)

(a)quenched from 4400 C

(disordered)(b) held 30 min at 3600 C and

quenched (partially ordered)

(c) slowly cooled from 3600 C to

room temperature (completelyordered).

Variation of the long rangeorder parameter s with

temperature for AuCu3 and

CuZn


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Unit cells of the disordered andordered forms of CuZn

Unit cells of the twoordered forms of AuCu

Variation of the scatteringfactor correction (f with

P/Pk see text for details, the

two points on the curveshow the corrections forthe scattering of Zn KEradiation by copper and

zinc atoms


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Calculated powder patterns of austenite andmartensite each containing 1.0 percent

carbon in solution Cr KE radiation.

Partial diffractometerpattern of an oil quenched

Ni-V steel containing about30 volume percentaustenite (K) chromium

radiation v filter


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Examples of residual stress

T = tension

C = Compression

Residual stress induced byplastic flow in bending

(a) loaded below elastic limit

(b) loaded beyond elastic limit

(c) unloaded shaded regionshave been plastically

strained


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Bar in pure tension, with X-rays reflected from planes

parallel to axis.

Diffraction from strainedtension axis vertical latticeplanes shown belong to the

same (hkl) set Np = reflecting

plane normal.


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Stresses at the surface of a stressedbody W3 = 0, the stress to bemeasured is WJ. Vector diagram ofplane spacing d for a tensile stressWJ.

Plane spacing diagram (b) and (c)Orientation of x-ray relative to specimen.Ns = normal to specimen surface Np =

normal to reflecting planes.

Use of a diffractometer for stressmeasurement

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