In order to judge the ZrW2O8 cerami

In order to judge the ZrW2O8 ceramics decompose or not, the phase compositions of the samples are investigated by XRD. Fig. 2a shows that the main phases of the cold-sintered samples are the cubic α-ZrW2O8 (P213, 01-083-1005) and orthorhombic γ-ZrW2O8 (P212121, 01-073-8457), while trace of the tetragonal ZrW2O7(OH)2(H2O)2 (I41cd, 04-019-3783) is found when the liquid phase content ≥ 10 wt%. The formation of ZrW2O7(OH)2(H2O)2 is triggered by the local hydrothermal reaction in the added liquid phase HS. The shapes of the diffraction peaks of the cold-sintered samples become blunter with the increase of the liquid phase content due to the generation of the internal stress and the accumulation of the glass phase. In order to eliminate the internal stress and excessive glass phase, the annealing treatment is adopted and the corresponding XRD patterns are shown in Fig. 2b, indicating that all the samples fabricated by CSP are the cubic ZrW2O8 without the decomposed phases (ZrO2 and WO3). Moreover, the shapes of the diffraction peaks recover to be sharper for the elimination of the internal stress and the crystallization triggered from the glass phase. From the analysis of the phase compositions, it is clear that the addition of the liquid phase won’t affect the final compositions of the ZrW2O8 samples fabricated by CSP.