The effect of pressure on density of NaCl [32] and Na3.256Mg0.128Zr1.872Si2PO12 (Mg-doped NASICON)[48] produced by CSP was studied. It was found that the densities increased with applied pressure (Fig. 4).Gonzalez-Julian et al. [36] reported that the increasing applied pressures can reduce the onset temperature of densification, and thus restrain the grain growth during densification.