A simple coordinate transformation method for quickly locating the features of interest in TEM samples

Area of Science:

• Materials Science
• Microscopy Techniques
• Nanotechnology

Background:

• Transmission electron microscopy (TEM) surveys are time-consuming due to limited fields of view in aberration-corrected instruments.
• Locating specific features of interest (FOIs) in TEM can be challenging and inefficient.
• Current methods may require specialized sample holders or grids, limiting universal application.

Purpose of the Study:

• To develop a simple and accurate method for rapidly locating FOIs in TEM samples.
• To improve the efficiency of sample searching in advanced scanning/transmission electron microscopes (S/TEM).
• To provide a universally applicable solution for FOI identification across various TEM setups.

Main Methods:

• A coordinate transformation method was developed using digital optical microscopy images of the sample and holder.
• Naturally occurring geometric patterns on the holder were used to establish a projective transformation between optical and electron coordinate systems.
• The method was implemented as a Gatan script for user-friendly, graphical interface-based operation.

Main Results:

• The developed method demonstrated accuracy in locating FOIs.
• It requires no modifications to the electron microscope or specimen holder.
• The technique eliminates the need for patterned grids or deposited markers, enabling universal application.
• Real-time navigation and tracking of sample motion were achieved via online communication and enlarged optical images.

Conclusions:

• This coordinate transformation method offers a significant improvement in the speed and ease of FOI identification in TEM.
• Its universal applicability and minimal equipment requirements make it a valuable tool for researchers using S/TEM.
• The Gatan script implementation provides an accessible, user-friendly interface for enhanced TEM sample navigation.