Portion of (a) NPD and (b) XRPD profiles for $\mathrm{Na}_{0.5} \mathrm{K}_{0.5} \mathrm{NbO}_{3}$ showing, at selected temperatures $70,150,350,550$ and 750 K, the evolution with temperature of the cubic reflections: left panel 100, centre panel 110 and right panel 111.
Portion of (a) NPD and (b) XRPD profiles for \mathrm{Na}_{0.5} \mathrm{K}_{0.5} \mathrm{NbO}_{3} showing, at selected temperatures 70,150,350,550 and 750 K, the evolution with temperature of the cubic reflections: left panel 100, centre panel 110 and right panel 111.