P1_4 The Importance of Absorption Corrections in Quantitative Transmission Electron Microscopy

Abstract

This article discusses the effects that absorption has on quantitative transmission electron microscopy and assesses the validity of the assumption that such effects can be neglected if the specimen thickness is below 100nm. Calculations of the absorption correction factor are made for the example case of healthy soft tissue. The threshold thicknesses at which the absorption becomes significant are found to be 150nm and 180nm for Carbon and Nitrogen respectively (with Oxygen as the comparison element). It is concluded that 100nm is an acceptable thickness assumption based upon this evidence, although for other elements the threshold thicknesses will be different. It would also be advisable to consider absorption effects when there is a large level of uncertainty in the thickness, a common occurrence in such experiments.