Plasmon-ratio imaging: a technique for enhancing the contrast of second phases with reduced diffraction contrast in...

A technique is proposed for reducing unwanted diffraction contrast when imaging second phases in crystalline materials using transmission electron microscopy. With the suggested name of plasmon-ratio imaging, the technique uses an energy-filtered imaging system to record and determine a ratio for two images taken at energies in the low loss region. Unlike core-loss imaging, the use of very thin specimens is not required. It is concluded that it is often possible to create a ratio image in which the contrast is dominated by energy loss, that is, chemical differences, rather than by diffraction effects.