LAUSR

Abstract The femtosecond laser plasma charge attachment induced transport (fs-plasma CAIT) technique is considerably extended and applied to study ion transport in a borosilicate glass. The technique is based on attaching polarity selected charge carriers from a fs-laser to the front side of a sample, which induces transport of mobile charge carriers in this sample. The plasma-CAIT spectrometer is placed into a housing allowing the control of the plasma medium and its pressure. A model system is described, which allows the determination of the internal resistance of the plasma. This in turn provides access to absolute ionic conductivities without the need of external calibration. The improved fs-plasma CAIT technique is applied to study alkali ion conductivity in a D263T glass by attachment of protons or deuterons from a hydrogen and deuterium plasma, respectively. The range of conductivities is extended by one and a half orders of magnitude compared to previous work. Ex-situ analysis of the irradiated D263T samples by time-of-flight secondary ion mass spectrometry (ToF-SIMS) revealed a replacement of sodium and potassium ions being the native mobile charge carriers in the glass by external proton and deuterons, respectively, over up-to 100 nm. The concentration depth profiles generated by the electrodiffusion involve a local pile-up of the potassium concentration above the bulk concentration and a concomitant further depletion of the faster sodium at the H+ / D+ diffusion front. The results are fully in line with previous observation in a Cs+ CAIT experiment. The significant advancement of the current work lies in the demonstration that alkali ion transport can be probed by using protons or deuterons as markers for replacement in the native sites of the alkali ions. Ultimately the plasma medium can be freely chosen from a large range of chemical species turning the plasma-CAIT technique into an almost universal tool to study DC transport in solid ionics.