d8discover-for-material-research.1: dr. h. r. reß © 1999 bruker axs all rights reserved d8...

D8DISCOVER-for-Material-Research.1: Dr. H. R. Reß© 1999 BRUKER AXS All Rights Reserved

D8 DISCOVER for Material Research


D8 DISCOVER - New Developments

D8 the modular diffractometer

D8 the fast diffractometer

D8 & the reciprocal space

D8 the learning diffractometer

D8 the Internet diffractometer


high accessibility and visibility of the experiment with maximum safety

– ergonomic workbench

– foldable lead glass doors

– optimal usage of space by octagonal base

separate cooling water circuit with advanced control mechanisms

D8 DISCOVER - freedom without Limits


Everything revolves around the sample - D8 DISCOVER and our Eulerian Cradle

-rotation -rotation

D8 DISOVER: 7 motorised degrees of freedom

X-translation Z-translation


The diffractometer supports up to 18 independent, physical axes

All physical axes of the diffractometer can be used for adjustment and measurement

– all axis are scanable

Virtual axes are defined by the software and used in the same way as physical axes

– mapping in real and reciprocal space

negligible positioning time (<60ms) with stepping motors and optical encoders (5000 lines)

– fast independent movement of any combination of axes in one scan (virtual axis)

D8 DISCOVER Keeps You Moving


LOWRESOLUTIONDIFFRACTION

HIGHRESOLUTIONDIFFRACTION REFLECTION

chemical compounds + - -crystal orientation + +/- -stress & strain + +/- -crystal size + +/- -layer thickness (crystalline layer) - + +layer thickness (amorphous layer) - - +roughness - +/- +lateral structured layers - + +lattice mismatch - + -relaxation - + -chemical composition +/- + +/-

Combination of X-ray scattering methods


UBC - our Universal Beam Concept for the D8 DISCOVER

UBC X-ray source: X-ray tube and Göbel Mirror

UBC Modules for the incident beam

UBC Modules for the diffracted beam

the D8 DISCOVER and the UBC offer a fitting solution for all applications

the D8 DISCOVER and the UBC can be designed around the sample

the D8 DISCOVER and the UBC are as individualistic as the samples

What are the components of the UBC?

What are the benefits of the UBC?


D8 DISCOVER - accept no Limits

fast and reproducible exchange of components

optimum positioning of the components on high precision dove tail tracks - no fixed positions


The UBC X-ray source: X-ray tube and Göbel mirror

Göbel Mirror

X-ray Tube

0.7 -1.0mm wideparallel beam

Göbel mirrors for Cr-, Co-, or Cu-radiation, 40mm or 60mm length

next generation Göbel Mirrors prepared on prefigured substrates

single mirrors for line and spot focus applications cross coupled mirror for spot focus applications


3” or 5” vacuum chuck for a precise, secure and reproducible sample fixing

Unique Knife Edge Collimator (KEC) for Reflectometry with the 1/4-circle Eulerian cradle

D8 DISCOVER for Diffraction and Reflectometry


goal: highest dynamical range, 9 orders of magnitude in intensity

Si

S iOx

S iO2

red: experimentblue: simulation

D8 DISCOVER for Reflectometry


UBC Modules: incident beam


UBC Modules: Beam Compressor

V-groove Germanium crystal with asymmetrical Ge 022 reflection optimised for Göbel mirrors

narrow (<0.2mm) beam with moderate divergence and high intensity (high brilliance)

for investigations with very small incident angles


GID with smallest incident angles

reflectometry with increased resolution and high intensity

UBC Modules: Beam Compressor


UBC Modules: Beam Expander

V-groove Germanium crystal with asymmetrical Ge 022 reflection optimised for Göbel mirrors

wide (>5mm) beam with low divergence and high intensity

for powder diffraction with high angular resolution requirements, parallel beam conditions and a wide illuminated area on the surface of the sample


high resolution in powder diffractionK1 separation

UBC Modules: Beam Expander


UBC Modules: diffracted beam


diffracted beam Göbel mirror for parallel beam conditions

very high reflectivity and good angular resolution

resolution between analyser and Soller slits

– reciprocal space maps of relaxed epitaxial layer structures

UBC Modules: diffracted beam


high intensity powder diffraction

reflectometry diffuse scattering

high intensity reciprocal space mapping

Twin Göbel Mirrors for parallel beam conditions


Twin Göbel Mirrors for parallel beam conditions

61 62 63 64 65 66 67 68 69 70

101

102

103

104

105

106

107

inte

nsit

y / c

ps

scansilicon waferSi(400)

IK1 : IK

Cu K

W L

Cu K

C

u K

Sqr

(C

ps)

0

10

100

1000

200

300

400

500

600

2-Theta - Scale

31 40 50 60

steel sample with copper radiation

High intensity powder diffraction

Improved CuKß suppression with Twin Göbel Mirror arrangement


D8 DISCOVER the Internet diffractometer

The D8 DISCOVER is accessed over

the Internet.

Every kind of measurement can be

started

watched

and stopped

using a Internet connection.


D8 Measurements from all over the world


And where is the reciprocal space?


D8 DISCOVER & the reciprocal space

The spots of the reciprocal space represent the allowed reflections - the Bragg equation is fulfilled

Eulerian cradle angles phi and chi define a cut through reciprocal space

the intensity distribution can be obtained by scans in and/or 2


D8 DISCOVER & the reciprocal space

HR EDIT with a graphical user interface for reciprocal space

support of the user by a general and a zoom view of reciprocal space

reciprocal lattice of substrate and epitaxial layer can be displayed

relaxed and strained heterostructures


HR Edit Reciprocal Space Scans

support of scans in qx, qz and arbitrary directions in reciprocal space

– fast characterization of heterostructures by selected scans; i.e. crystal truncation rod, relaxation line ....

scans can be created, edited and deleted by graphical or dialog based input


hkl, q and Q reciprocal lattice units are supported

sections of reciprocal space can be defined optional in angels or in reciprocal lattice units

– reduction of measurement time

all physical and virtual axis can be nested in 3 loops layers

– e.g. reciprocal space maps at different (x,y) positions of inhomogeneous or structured samples

HR Edit Real and Reciprocal Space Maps


All new components of Diffracplus support automation by a simple script language

The script language offers a direct interface to all components of the diffractometer

– supplied scripts for sample adjustment

– integration of new measurement concepts by the user Set of functions for determination of peak maximum and interpolation

– individually suitable and extendable strategies by use

of the powerful script language Intelligent alignment and measurement strategies that can be taught

by the user experience

Automation of routine measurement

Diffracplus with Script Language


HRXRD Evaluation of measurements

Si

SiGe

Si

Simple evaluation of thickness, composition and mismatch of epitaxial layers

– starting point for simulation

Advanced interpretation of the scattering profile by simulation

– one of two commercial programs performing correct calculations for thin layers (Grundmann[1], Zaus[2])

[1] M. Grundmann, subm. PRL (1999)[2] R. Zaus, J. Appl. Cryst. 26, 801 (1993)


General Area Detector Diffraction Solution

2-D position sensitive detector

Collects data from the entire Debye ring without moving

True Photon counter

200 micron spatial resolution

Variable detector distances 50 - 300 mm for resolution or intensity

D8 DISCOVER with GADDS: in Fact a Member of the D8 Family

d8discover-for-material-research.1: dr. h. r. reß © 1999 bruker axs all rights reserved d8...

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