Atom probe tomography of lithium-doped network glasses

• Atom probe tomography is performed on ion conducting glasses.
• Redistribution of ions during the measurement is observed.
• An electrostatic model is applied to describe the electric field and ion diffusion.
• Measurement is conducted of the absolute temperature during laser pulses.

Li-doped silicate and borate glasses are electronically insulating, but provide considerable ionic conductivity. Under measurement conditions of laser-assisted atom probe tomography, mobile Li ions are redistributed in response to high electric fields. In consequence, the direct interpretation of measured composition profiles is prevented. It is demonstrated that composition profiles are nevertheless well understood by a complex model taking into account the electronic structure of dielectric materials, ionic mobility and field screening. Quantitative data on band bending and field penetration during measurement are derived which are important in understanding laser-assisted atom probe tomography of dielectric materials.