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X-RAY DIFFRACTION FACILITIES at the department of Materials Science & Engineering

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Contact details

Hendrikx, Ruud
Mechanical, Maritime and Materials Engineering (3mE), Department of Materials Science and Engineering
Mekelweg 2, 2628 CD Delft
Tel : +31 (0)15 27 82255
E-mail : r.w.a.hendrikx@tudelft.nl
Website : Open website

General Information

Instrument:

X-RAY DIFFRACTION FACILITIES at the department of Materials Science & Engineering

Location:

Department of Materials Science and Engineering, Room 3B-1-02, Mekelweg 2, Delft

Key words:

identification, reflectometry, thin-film, humidity, high temperature, crystallite size, analysis, strain, orientation, texture, crystallographic, stress, diffractometer, diffraction, X-Ray, Rietveld, refinement

Main application:

X-ray diffraction is a versatile, non-destructive technique that can be used to investigate the structure of materials. X-ray diffraction patterns can be used to determine the crystal structure and crystalline compounds present in a sample. More advanced applications are (1) the determination of texture or crystallite orientations, (2) the analysis of the state of stress through measuring the lattice-spacing changes caused by external or internal forces and (3) estimating the crystallite size and dislocation densities by full diffraction profile analysis.

X-ray reflectometry enables the investigation of thin film material typical of thicknesses of about a few hundred nanometer. The reflectometry experiments allow the determination of (1) the total film thickness (2) density varations in thin film single or multilayer systems and (3) surface roughness.

Instrument specification

1. D8-Discover diffractometer system with Eulerian cradle.
The tilt and rotation angles of the Eulerian cradle in combination with the parallel beam geometry, obtained by a polycapillary system, makes this system especially suited for crystallographic texture and stress determination. The sample stage includes computer controlled X, Y and Z movements.

 

2. D8- Advance theta/2theta vertically mounted diffractometer system with Vantec position sensitive detector.
This instrument has a special track system, which makes it flexible in changing over to other measurement geometries, e.g. for transmission or capillary measurements. Due to the high counting efficiency of the Vantec detector, short measurement times are possible. A Vario-1 incident-beam alpha1 monochromator can be mounted.

 

3. D5005 theta/2theta vertically mounted diffractometer system with incident-beam CuK-alpha1 monochromator and a gas-filled metal wire position sensitive detector (PSD). This instrument has an excellent angular resolution combined with a high counting efficiency. Ideal for phase identification, as well as for detailed analysis of the diffraction maxima. The instrument is less suitable for materials with high fluorescence on Cu K-alpha radiation.

 

4. D5005 theta/theta vertically mounted diffractometer system with wide range high and low temperature attachment and humidity generator.
In this instrument, the sample stage remains in a fixed horizontal position during scanning, which means that even liquids can be measured. A temperature chamber can be mounted that makes it possible to measure in the range from room temperature to 1600 oC or from -190 oC to 450 oC in various atmospheres or in vacuum. The temperature is computer controlled which enables to program the temperature process. The humidity chamber generates wet gases in the range 10 - 99 %RH at room temperature.



5. X’Pert PRO Materials Research Diffractometer (MRD)
This system can handle a wide range of applications, and is especially suitable for thin film analysis applications such as: rocking curve analysis and reciprocal space mapping, reflectometry and thin film phase analysis, and residual stress and texture analysis.


Useful information
The diffractometers are manufactured by Bruker-AXS and PANalytical. They can be equipped with various attachments for special applications. Special sample holders and sample preparation methods are available. A tensile device for in-situ stress measurements can be mounted.
The irradiated area on the specimen is usually about 10 x 15 mm2, but can be made as small as 1 x 1 mm2. The effective penetration depth depends on the material and the wavelength used and falls in the range of 2 - 20 μm.
For powder material, the minimum amount needed to make a specimen is about 10 mg; for quantitative analysis about 0.5 g is needed.
Specimens made from bulk materials should fit within a circle of 500 mm diameter and should not be thicker than 10 mm; the surface should be as flat as possible.
For reflectivity measurements the sample requirements are: sample should be flat (e.g film on silicon single crystalline substrate), film roughness and substrate roughness less than 3 nm, surface area more than a few mm2 , film thickness of the order of a few hundred nanometers.