Atom probe tomography of lithium-doped network glasses

Area of Science:

• Materials Science
• Solid-State Physics
• Analytical Chemistry

Background:

• Lithium-doped silicate and borate glasses exhibit high ionic conductivity despite being electronic insulators.
• Mobile lithium ions redistribute under high electric fields during laser-assisted atom probe tomography (LA-AP), complicating compositional analysis.
• Accurate interpretation of LA-AP data from dielectric materials is crucial for understanding their properties.

Purpose of the Study:

• To develop a comprehensive model that explains the observed composition profiles in Li-doped glasses during LA-AP.
• To account for the influence of electronic structure, ionic mobility, and electric field screening on ion redistribution.
• To derive quantitative data on band bending and field penetration relevant to LA-AP measurements.

Main Methods:

• Utilized laser-assisted atom probe tomography (LA-AP) to analyze Li-doped silicate and borate glasses.
• Developed a complex theoretical model incorporating electronic structure, ionic mobility, and field screening effects.
• Analyzed the redistribution of mobile Li ions under high electric fields during the tomography process.

Main Results:

• Demonstrated that a complex model accurately explains composition profiles despite Li ion redistribution.
• Quantified band bending and field penetration phenomena occurring during LA-AP measurements.
• Established a framework for understanding and correcting for measurement artifacts in dielectric materials.

Conclusions:

• The redistribution of Li ions in Li-doped glasses during LA-AP can be accurately modeled.
• Understanding electronic structure and ionic transport is key to interpreting LA-AP data from insulators.
• The derived quantitative data provides critical insights for advanced materials characterization using LA-AP.