Phase field calculated effective diffusivity D _eff of Li vacancy in anti-perovskite Li ₃ OCl is shown as a function of average grain sizes. Li vacancy segregation reinforces the negative contribution of grain boundaries on the overall Li diffusion.

In order to understand the effect of polarization frequency and temperature on polarization rule of tourmaline, the ferroelectric hysteresis loops of three kinds of tourmaline samples are measured in different polarization conditions. It is demonstrated that the spontaneous polarization along c-axis of tourmaline is larger than that perpendicular to c-axis. Furthermore, the polarization frequency and temperature have great influences on the ferroelectric hysteresis loop of tourmaline, inferring that the polarization forms of tourmaline may be composed of turning-direction polarization of electric dipole and thermionic relaxation polarization.