Fig. 1(b) shows the XRD patterns of

Fig. 1(b) shows the XRD patterns of LiF ceramics obtained at various processing temperatures. All diffraction patterns may be indexed based on the LiF crystal structure (JCPDS #45−1460) with no additional diffraction peaks related to the existence of secondary phases or structural phase transformations. Rietveld refinements of XRD patterns are carried out based on the Fm3(_)m LiF structure with the calculated and measured profiles shown in the supporting information, Figure S1. The calculated lattice parameters and the reliability factors are listed in Table 1. The CS process and subsequent annealing have little effect on phase purity, crystal structure or lattice parameters.