t-EBSD AnalysisTKD (Transmission Kikuchi Diffraction, sometimes referred to as t-EBSD), used for the collection of EBSD data in transmission mode in the SEM, is increasingly applied for materials characterisation at the
nanoscale.

 

Despite significant technological developments in recent years, the conventional EBSD technique is still limited by the pattern source volume to resolutions in the order of 25-100 nm. This is insufficient to measure accurately truly nanostructured materials (with mean grain sizes below 100 nm).

A new approach to SEM-based diffraction has emerged. This uses an electron-transparent sample coupled with conventional EBSD hardware and software. This technique, referred to as transmission EBSD (t-EBSD: Keller and Geiss, 2012) or SEM Transmission Kikuchi Diffraction (TKD: Trimby, 2012) has been proven to enable spatial resolutions better than 10nm. 

TKD advantages
 

  • Spatial resolution better than 10 nm
  • Ideal for the routine characterisation of nanostructured material
  • EBSD analysis of highly deformed samples

AZtec is the system of choice for TKD analysis. It includes an optimised TKD mode as standard for acquiring the most accurate maps - even at the nanometre scale. EBSPs collected in transmission mode have a gnomonic distortion and this innovative technology detects the bands in these patterns more accurately, ultimately delivering a higher hit rate.

You can download TKD application notes below.

TKD Application notes

Determining optimum sample thickness for TKD using AZtec

This application note discusses the effect of sample thickness and density on TKD results.

PDF 7.75MB
TKD Analysis in AZtec

This application note describes some of the challenges when using TKD and how application of the AZtec EBSD system overcomes them.

PDF 1.91MB
TKD Application note

Improving the spatial resolution of EBSD in the SEM by TKD

PDF 624KB

TKD Sample Holder

A new Transmission Kikuchi Diffraction sample holder is available from Oxford Instruments here. It is designed to hold thin (TEM) samples at a geometry so transmitted kikuchi patterns can be collected on the screen of the EBSD detector. 

  • Can be used on a range of SEM types
  • Easy to use, and eases the locating and holding of delicate thin samples:
    • The fixing screws do not need to be removed when changing or loading samples
    • The screws are loosened and the top plate (which holds the sample in position) can be lifted and slid back out of the way
    • When the sample is located the top plate is replaced and the screws tightened
    • There is a recessed section in the lower plate so that the sample can be easily positioned
  • The entire top plate can be inverted, should the sample be mounted upside down
  • In addition, the plate can be mounted for conventional EBSD
  • The sample holder includes a beam stop to prevent the beam which passes through the thin sample being reflected back up onto the EBSD screen, and therefore interfering with the EBSP

TKD Holder