Abnormal Li diffusion in β-LiGa by the formation of defect complex

Nanoscale diffusion tracing by radioactive8Li tracer

“…This analysis procedure is essentially the same as that for the previous measurements. 9,10) In addition, it should be noted that the experimental values with the high gate are well reproduced by the simulation with the same diffusion coefficient that best reproduces the normalized ¡-particle yields in the low gate, as shown in Fig. 3.…”

“…We developed an online lithium diffusion tracing method that involves implanting a short-lived radioactive beam of 8 Li as a diffusion tracer into the sample of interest at a depth of several micrometers. 9,10) The radioactive lithium isotope 8 Li is an ¡ emitter immediately after ¢ decay with a half-life of 0.84 s. Measuring the ¡ particles emitted from decaying 8 Li primarily implanted into the sample as a function of time allowed us to measure lithium diffusion coefficients in Li ionic conductors with an accuracy of about 20% and a sensitivity down to several 10 ¹10 cm 2 /s: The method is sensitive to micrometer scale lithium diffusion because the tracers used in the method undergo micrometer-order diffusion along the implantation depth. No diffusion effects were observed when applying the method to measuring lithium diffusion coefficients in LiCoO 2 even at a temperature of 573 K.…”

“…11, that the detection limit of the Li diffusion coefficients can be improved to 10 ¹12 cm 2 /s by detecting ¡ particles emitted in a narrow angular range of 10°(e.g., 10 « 5°) relative to the sample surface, which is irradiated with low-energy 8 Li of 8 keV. Note that in the previous method sensitive to micro-scale diffusion, 9,10) the angles subtended by the ¡ particle detectors were within 63 « 14°, and the incident energy of 8 Li was about 4 MeV. The implantation depth (d) of 8 Li was then set to be close to a range around 10 µm of ¡ particles in the previous method, while it was around several 10 nm in the present method.…”

Tokai Radioactive Ion Accelerator Complex (TRIAC): present and future

“…In the experiment, they measured -particles, emitted fromdecaying 8 Li, coming out of the sample of interest after implanting RIBs, and have found that the timedependent yields of -particle from the diffusing 8 Li primarily implanted is a good measure of the Li diffusion in the sample. The method has been successfully applied to measure the lithium diffusion coefficients in a typical defect-mediated lithium ionic conductor of LiGa [7], well demonstrating that the method is very effective to measure the diffusion in the micro-meter regime per second. As shown in Fig.…”

Toward Online Nanoscale Diffusion Measurements Using Radioactive 8Li Tracer

“…We have developed an online lithium diffusion tracing method using a short-lived radioactive ion beam of 8 Li and successfully applied it to measure diffusion coefficients in Li ionic conductors. [1][2][3] The 8 Li decays through À emission to 8 Be with a half-life of 0.84 s, which immediately decays into two particles with energies distributed around 1.6 MeV with a full width at half maximum (FWHM) of 0.6 MeV. In the method, 8 Li ions with an energy of several MeV are implanted into a solid sample of interest to an implantation depth of several micrometers, where most particles stop in the sample.…”