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T hesaurus of X-Ray D iffractionNila Huda - 1408100045 Kelas A

X-Rays

Electromagnetic radiation of shorter wavelength than ultraviolet radiation

produced by bombardment of atoms by high-quantum-energy particles. The range

of wavelengths is 1011 m to 109 m.

X-Ray Diffraction

A non-destructive analytical technique for identification and quantitative

determination of the various crystalline forms, known as phases.

Powder Diffraction

A scientific technique using X-ray, neutron, or electron diffraction on powder or

microcrystalline samples for structural characterization of materials.

Single-crystal Diffraction

A non-destructive analytical technique which provides detailed information about

the internal lattice of crystalline substances, including unit cell dimensions, bond-

lengths, bond-angles, and details of site-ordering. Directly related is single-crystal

refinement, where the data generated from the X-ray analysis is interpreted and

refined to obtain the crystal structure.

Diffractometer

A measuring instrument for analyzing the structure of a material from the

scattering pattern produced when a beam of radiation or particles (such as X-rays

or neutrons) interacts with it.

Crystalline

Arranged atoms in a regular pattern, and there is as smallest volume element thatby repetition in three dimensions describes the crystal.

Amorphous

Arranged atom in a random way similar to the disorder we find in a liquid. Glasses

are amorphous materials.

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Unit cellthe smallest three dimensional box which can be stacked to describe the 3D lattice

of a solid.

Crystal system

A method of classifying crystalline substances on the basis of their unit cell. There

are seven crystal systems. If the cell is a parallelopiped with sides a, b, and c and if

is the angle between b and c, the angle between a and c, and the angle

between a and b, the systems are: (1) cubic (2) tetragonal (3) rhombic (or

orthorhombic) (4) hexagonal(5) trigonal(6) monoclinic(7) triclinic.

Crystal Lattice

A regular three-dimension distribution (cubic, tetragonal, etc.) of atoms in space.

These are arrange so that they form a series of parallel planes separated from one

another by a distance d, which varies according to the nature of the material. For

any crystal planes exist in a number of different orientations- each with its own

specific d-spacing.

Miller Index

defines the orientation of the plane within the unit cell.

Monochromator

a device used to disperse a broad spectrum of radiation and provide a continuous

calibrated series of electromagnetic energy bands of determinable wavelength orfrequency range.

Detector

Generally a photomultiplier tube that recovers information of interest contained in

a modulated wave.

Diffractogram (diffraction spectrum)

A plot of reflected intensities versus the detector angle 2-THETA or THETA

depending on the goniometer configuration.

Intensity

States the large number of diffraction grating which indicates the crystallinity of a

material. The higher intensity, the more crystallite a material measured

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Angle 2-THETAThe angle of diffraction that indicates phases of crystal of the material measured.

Fingerprint

Evidence for the presence or the identity of a substance that is obtained by

techniques such as spectroscopy, chromatography, or electrophoresis.

Broadening of spectral lines

A widening of spectral lines by collision or pressure broadening, or possibly by

Doppler effect.

Half-width

Half the width of a spectrum line (or in some cases the full width) measured at half

its height.

Reference material

A material or substance whose properties are sufficiently well established to be

used in calibrating an apparatus, assessing a measurement method, or assigning

values to other materials.

Bragg's Law

Refers to the simple equation: n= 2d sin that explain why the cleavage faces of

crystals appear to reflect X-ray beams at certain angles of incidence (, ). The

variable d is the distance between atomic layers in a crystal, and the variablelambda is the wavelength of the incident X-ray beam; n is an integer.

Scherrers Formula

The formula that explaine how to know crystallite thickness (t) from the peak of

diffraction spectrum by this simple equation: t = 0,89 / B cos. B is full width at

half max of the peak.

Rietveld refinement

A technique used in the characterisation of crystalline materials. The neutron and

x-ray diffraction of powder samples results in a pattern characterised by reflections

(peaks in intensity) at certain positions. The height, width and position of these

reflections can be used to determine many aspects of the materials structure.