Analysis of coatings with increased sensitivity

A commonly used technique in X-ray diffraction analysis of randomly oriented polycrystalline coatings is to increase the sensitivity of the XRD signal by applying a grazing angle of incidence of the X-rays. In such a geometry, classical residual stress analysis is no longer possible. To overcome this limitation, Malvern Panalytical and its collaboration partner, the Max Planck Institute Stuttgart (Germany), have developed pioneering modifications to the classical sin²ψ stress analysis. Data from multiple {hkl} peaks are combined and a conversion algorithm calculates true ψ-tilts for all possible combinations of instrument angles.

Analysis of coatings with strong preferred orientation

A preferred orientation is sometimes deliberately applied to coatings in order to enhance their properties, e.g. to maximize their wear resistance. Like coatings with increased sensitivity, traditional sin²ψ stress analysis is not possible on materials with preferred orientation. Data is instead collected by applying a chi tilt to normal symmetrical scans in order to measure lattice planes, which are not parallel to the sample surface. Stress Plus allows data from different {hkl} peaks, each with their own tilt, to be combined in one modified sin²ψ plot. Stress Plus automatically accounts for peak shifts due to stress, assigning correct Miller indices and identifying coating and substrate or sub-layer peaks.

Easy to set up and use 

Residual stress measurements on coatings are fully supported in both Data Collector and Stress Plus. Data Collector contains special measurement programs to set up the data collection strategy. Stress Plus takes all parameters from the .XRDML file and generates the residual stress values in the same intuitive way as the Stress program.

Experimental freedom

Stress Plus calculates all intermediate results and final stress data instantly. The influence of all parameters is directly reflected in the final result. The option to analyze combined data sets from multiple data files provides complete experimental freedom. Additional data can be added at any time. User-configurable defaults and instant recalculation of results based on a change of input parameters, make Stress Plus ideal for both routine analysis and research applications.

Current version

Version 2.1

Measurement systems

The following systems can be used for collecting and storing stress data:

  • Empyrean with Data Collector 4.0 and higher
  • X’Pert PRO with X’Pert Data Collector 1.3 or 2.0 and higher
  • X’Pert³ with the latest version of Data Collector

Recommended configuration

Operating system: Windows 7 Professional (64-bit) operating system
Processor: 1 GHz or faster 32-bit (x86), or 64-bit (x64) processor
Internal memory: 1 Gbyte 
Free hard disk space: 16 Gbytes (or more)
Monitor: Super VGA monitor (17 inch or more) with a desktop area of 1024*768 pixel or more

The minimum configurations for the supported operating systems are:

  • Windows XP Professional edition (32-bit) 
  • Windows 7 Professional (64 bit) operating system