Non-stoichiometric spinel compositions with molar ratio of MgO:Al₂O₃ = 1:2 and 2:1, were prepared via single-stage reaction sintering technique at 1550°-1600°C using commercial grade oxide reactants. The effect of different rare-earth oxides, viz. CeO₂, La₂O₃ and Y₂O₃ at 2 wt% level on the properties of different spinel batches was studied. Y₂O₃ was found to favour densification in both the spinel batches while CeO₂ and La₂O₃ were found to favour densification only in the MgO-rich spinel compositions. Phase analysis revealed that Y₂O₃ containing Al₂O₃-rich spinel has a secondary phase with similar crystal structure to spinel (both cubic) and improved densification, while in the MgO-rich condition, Y₂O₃ remained as secondary phase and assisted in densification. CeO₂ and La₂O₃ in Al₂O₃-rich samples formed secondary phases with different crystal structures and resulted in reduced densification. While in MgO-rich condition, CeO₂ (cubic) did not react with Al₂O₃ and La₂O₃ formed a secondary phase with similar crystal structure as that of spinel and therefore assisted in densification. Addition of rare-earth oxides led to improvement in strength of MgO-rich spinels and maximum improvement in strength was observed with the addition of yttria.

采用商业级氧化物反应物在1550°-1600°C下通过单阶段反应烧结技术制备了摩尔比MgO:Al ₂ O ₃ = 1:2和2:1的非化学计量尖晶石组合物。不同稀土氧化物的影响，即。研究了 2 wt% 含量的CeO ₂、La ₂ O ₃和 Y ₂ O _{3对不同尖晶石批次性能的影响。}发现Y ₂ O ₃有利于两种尖晶石批次的致密化，而 CeO ₂和 La ₂ O ₃发现仅在富含 MgO 的尖晶石组合物中有利于致密化。物相分析表明，含有富Al ₂ O _{3尖晶石的Y 2} O ₃具有与尖晶石（均为立方体）相似晶体结构的第二相，并且致密化得到改善，而在富MgO条件下，Y ₂ O ₃仍为第二相并协助致密化。富含Al ₂ O _3的样品中的CeO ₂和La ₂ O 3 形成具有不同晶体结构的第二相并导致致密化降低。而在富MgO条件下，CeO ₂（立方）不与Al ₂ O ₃反应，La ₂ O ₃形成与尖晶石晶体结构相似的第二相，因此有助于致密化。添加稀土氧化物导致富MgO尖晶石的强度提高，并且在添加氧化钇时观察到强度的最大提高。