Fig. 1: Crystal structure analysis.

Crystal structure of the NaLaCl₄ (the white ball: vacancy) (a). Rietveld refinements of NaLaCl₄-HM (b), Na_0.9La_0.9Zr_0.1Cl₄-HM (c), Na_0.8La_0.8Zr_0.2Cl₄-HM (d), Na_0.7La_0.7Zr_0.3Cl₄-HM (e) and lattice parameters of Na_1−xLa_1−xZr_xCl₄-HM obtained from XRD refinement (f).