Microbeam analysis - Analytical electron microscopy - Method for determining the number density of nanoparticles in a metal

This document describes the application of transmission electron microscopy/scanning transmission electron microscopy (TEM/STEM) techniques to the determination of nanostructures in metallic materials: Method for the number density of second phase particles at meter scale: This document is applicable to the determination of the number density of second phase particles dispersed in metal materials with a particle size ranging from a few nanometers to tens of nanometers: The average size of the particles to be measured should be less than about 1/3 of the thickness of the TEM sample, and the particles in the sample should not overlap each other in the TEM image: The samples with particle size not in this range can be executed as a reference, and other crystalline materials can be executed as a reference: This method is not suitable for determining the number density of aggregated second phase particles:

Note 1 The minimum particle size that can be measured depends on the resolution of the TEM/STEM equipment used and the experimental technique employed:

Note 2: The second phase particle size to be measured is usually in the range of 5nm to 40nm:

Note 3: If there is overlap of second phase particles in the TEM image, the uncertainty of particle counting will increase: