Nanoscale diffusion tracing by radioactive 8Li tracer

We have developed a nanoscale diffusion measurement method using an α-emitting radioactive 8Li tracer. In this method, while implanting a pulsed 8 keV 8Li beam, the α particles emitted at a small angle (10°) relative to the sample surface were detected as a function of time. The method has been successfully applied to measuring lithium diffusion coefficients for an amorphous Li4SiO4-Li3VO4 (LVSO) thin film with a thickness of several hundred nanometers, demonstrating that the present method is sensitive to diffusion coefficients down on the order of 10−12 cm2/s, which is more sensitive by about two orders of magnitude than that previously achieved.