Effects of Gd2O3 doping on the structure and the conduction mechanism of K2Mg2(SO4)3 langbeinite ceramics: A comparative study

•Gd2O3 doped langbeinite materials were elaborated via the solid state reaction method.•The materials are considered as ionic semiconductors in the [633–713 K] temperature range.•KMgSGd (x = 0.5 mol%) was selected as the best ionic conductor because of its lowest value of activation energy.•Conduction within these materials is done by migration of mobile cations and it explained by the CBH model.