Exploring the influence of focused ion beam processing and scanning electron microscopy imaging on solid-state...

Area of Science:

• Materials Science
• Solid-State Chemistry
• Electron Microscopy

Background:

• Reliable transmission electron microscopy (TEM) sample preparation is crucial for materials analysis, especially for beam-sensitive materials.
• Focused ion beam (FIB) is a common preparation technique, but its induced structural modifications are not fully understood.
• Insulating solid-state electrolytes are prone to damage from electron and ion beams.

Purpose of the Study:

• To investigate the impact of electron and Ga+ ion beams on insulating solid-state electrolytes.
• To understand the mechanisms behind beam-induced structural and chemical changes.
• To identify effective methods for stabilizing these electrolytes during TEM sample preparation.

Main Methods:

• Focused ion beam (FIB) preparation of solid-state electrolytes.
• Exposure to electron and Ga+ ion beams at varying doses and acceleration voltages.
• Analysis of morphological and chemical changes using scanning electron microscopy (SEM) and TEM.
• Evaluation of stabilization techniques including gold coating and cryogenic preparation.

Main Results:

• Significant lithium/sodium whisker growth was observed on lithium phosphorus oxynitride, Na-β"-alumina, and NaSICON due to both electron and ion beam exposure.
• Whisker growth occurred at low doses, leading to substantial changes in chemical composition.
• Surface charging was identified as a primary cause of metal whisker growth.

Conclusions:

• Electron and ion beam irradiation can induce detrimental whisker growth in insulating solid-state electrolytes.
• Gold coating and cryogenic preparation are effective strategies to mitigate beam damage and stabilize electrolytes for imaging.
• Understanding these beam-sample interactions is vital for accurate TEM analysis of sensitive materials.