Microanalysis and electron energy loss spectroscopy of polymers

Abstract

Analytical electron microscopy has progressed in recent years such that quantitative chemical information can be obtained from very small volumes of sample. In principle, the composition of regions on the order of a few namometers in both diameter and thickness can be determined using energy dispersive x-ray analysis (EDS) and electron energy loss spectroscopy (EELS) [1,2], In the case of organic polymers the limitations to quantitative microanalysis are generally due to the sample and not to the instrument. Radiation damage induced mass loss often proves to be the constraining factor in obtaining quantitative information from small volumes of sample [3], The principles and processes of radiation damage in organic materials and polymers can be found in various review articles [4,5].The principles underlying both analytical x-ray spectroscopy and electron energy loss spectroscopy are closely related. When an electron in the incident beam loses energy (i.e. inelastically scattered) by "knocking" out an inner shell electron from an atom present in the sample there are two aspects that are of value for compositional analysis.