Investigation of Sm₂O₃ additive on mechanical and electrical properties of Li₂O‐ stabilized β″‐alumina electrolyte

Abstract

Li2O‐ stabilized β″‐alumina was synthesized by the double zeta process. The effect of Sm2O3 additive as the sintering aid, on microstructure, mechanical and electrical properties of Li2O‐ stabilized β″‐alumina ceramics was studied by means of X‐ray diffraction, field emission scanning electron microscope, biaxial flexure test and ionic conductivity measurement. The results indicated that both the fracture strength and the ionic conductivity of the sample containing 0.2 wt% Sm2O3 improved approximately 52% and 54%, respectively, that can be attributed to its higher density, higher amount of β″‐Al2O3 phase and more uniform microstructure.

Low-temperature sintering of sodium beta alumina ceramics using nanosized SnO2 sintering aid

“…Some improvement of the sintering behaviour was observed for the samples with 2 mol% of nanosized SnO 2 , but not as pronounced as when just 1 mol% of nanosized SnO 2 was added. Figure 2 shows the typical X-ray diffraction patterns of the samples sintered at 1620°C which confirms the presence of Na 1.67 Al 10.67 Li 0.33 O 17 crystalline phase [6,27]. According to XRD patterns, no impurity phases have been detected for the samples prepared with 0.5 and 1 mol% of nanosized SnO 2 .…”

“…However, when the amount of SnO 2 increased to 2 mol%, a few unknown diffraction peaks were detected. So, it is proposed that, for the samples with 0.5 and 1 mol% of nanosized SnO 2 , Sn 4+ can be incorporated into the sodium beta alumina crystal lattice [6]. Decrease in the density of the sample by increasing amount of SnO 2 from 1 to 2 mol% can also be attributed to the presence of impurity phase in this sample.…”

“…For most applications, microstructural control usually means achievement of the high density, small grain size and homogeneous microstructure [1]. Using sintering aids is a well known method for altering microstructure during sintering of ceramic materials which could modify densification characteristics and improve mechanical, magnetic and electrical properties of the fired sample [2][3][4][5][6]. In recent years, it has been shown that using sintering aids with nanoparticle size can reduce the required amount of sintering aids even down to 1 mol% and can also improve properties of the sintered products [7][8][9][10][11][12][13].…”

“…It would be possible to lower the sintering temperature and overcome the mentioned difficulties by using sintering aids. The effects of different sintering aids including ZnO, MgO, Nb 2 O 3 , Sm 2 O 3 and nano-CuO on the densification behaviour and properties of sodium beta alumina electrolyte have been investigated [6,[22][23][24].…”