Transmission Electron Microscopy (TEM) Through Focused ION Beam (FIB) from Vitrified Chromium Wastes

Abstract

This study shows how the Focused Ion Beam (FIB) has been applied to vitrified materials obtained from chromium

wastes. Due to the issues arising during conventional Ar+ ion milling, it was necessary to thin these samples using

FIB. Difficulties came from the heterogeneous size between chromium spinels and the residual glass phase. The FIB

was applied to obtain thin foils from vitrified materials. These brittle and heterogeneous samples result in specimens

with many perforations and chipping when using conventional thinning below 100 nanometers. Alternatively, FIB

allowed thinning in the range of 60 - 80 nanometers from specifically selected areas such as the areas containing

spinel crystals Mg(Al,Cr)2O4 in order to facilitate the final Transmission Electron Microscopy (TEM) observations. In

this paper, FIB is shown to be a very powerful microtool as a brittle samples preparation method as well as providing

an alternative way for performing conventional ceramography and Ar+ ion milling. FIB is a much less destructive

method with greater observed capacity in the quantity and analysis of microcrystalline phases.