Analysis of process parameters affecting the crystal orientation of Na+-β″-Al2O3 solid electrolyte in one-step synthesis cum sintering process

Na+-ion conducting Na+-β"-Al2O3 solid electrolyte has been prepared by a one-step synthesis cum sintering process as an alternative to the conventional solid-state reaction process, and the degree of crystal orientation was evaluated by the Lotgering factor with XRD Cu-Kα radiation source. In order to analyze the process parameters which affect the value of Lotgering factor, two experiments were carried out separately, i.e. on dwelling at various temperatures before sintering and different granule sizes selected in the press-forming. The Na+-β"-Al2O3 fabricated by one-step synthesis cum sintering process fully crystalized without any secondary phase. As a result, lower values of Lotgering factor indicated a higher ionic conductivity of Na+-β"-Al2O3. Among the processes including the heat treatment step, the smallest Lotgering factor was observed in the dwelling temperature of 1000 °C for 2 h. In terms of granule size, the smaller grain size showed the lower Lotgering factor.