Transmission Kikuchi diffraction (TKD), or tansmission EBSD (t-EBSD), is a related technique to EBSD. In TKD the sample has to be electron transparent and is mounted horizontally (sample surface perpendicular to the electron beam) or at a slight tilt (up to 20°). Electrons transmitted through the sample, and diffracted on their way out from the lower surface are detected . A spatial resolution of a few nanometres is possible, compared with tens of nanometres for EBSD. TKD can be performed with a conventional EBSD system by simply using a bespoke sample holder. This is referred to as the off-axis geometry with the vertical detector below, but to the side of the sample.
References
Trimby, P. W., Cao, Y., Chen, Z., Han, S., Hemker, K. J., Lian, J., Liao, X., Rottmann, P., Samudrala, S., Sun, J., Wang, J. T., Wheeler, J., & Cairney, J. M. (2014). Characterizing deformed ultrafine-grained and nanocrystalline materials using transmission Kikuchi diffraction in a scanning electron microscope. Acta Materialia, 62, 69. https://linkinghub.elsevier.com/retrieve/pii/S1359645413007118
Keller, R. R., & Geiss, R. H. (2012). Transmission EBSD from 10 nm domains in a scanning electron microscope. Journal of Microscopy, 245, 245. https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2818.2011.03566.x