【摘要】 以硫酸铝为原料,用溶胶凝胶法制备含有添加剂的Al（OH）₃前驱体,在Na2SO₄-K₂SO₄熔盐中煅烧合成α-Al₂O₃粉体,研究了Na₃PO₄·12H₂O和TiOSO₄添加剂对α-Al₂O₃形貌的影响,片状氧化铝的形成机理以及添加剂的作用机理.添加剂Na₃PO₄·12H₂O中的磷酸根离子在晶体表面的吸附可抑制氧化铝晶体在厚度方向上的生长,并减少粉体之间的团聚和交错生长,获得无团聚且分散性良好的氧化铝薄片;加入TiOSO₄后,钛离子的进入会提高铝空位浓度,从而改变晶体各晶面的生长速度,促使其较为规则形貌的形成.从而制备出形貌规则、大小均匀,无团聚的片状α-Al₂O₃.更多还原

【Abstract】 Plate-likeα-Al₂O₃ single crystal particles were successfully synthesized in Na₂SO₄- K₂SO₄ flux using Al（OH）₃ as precursor,which were produced by sol-gel method.The influence of additives such as titanyl sulfate and trisodium phosphate on the morphology ofα-Al₂O₃ powders was focused.The crystal growth mechanism of plate-likeα-Al₂O₃ and the action mechanism of the additives were studied. When trisodium phosphate is added,the phosphate ions will be adsorbed on the crystal faces ofα-Al₂O₃, leading to the reduction of the platelet thickness and the aggregations,but the shape of platelets is still irregular.When both trisodium phosphate and titanyl sulfate are added,the growth velocity of some crystal faces may be changed owing to the extra Al³⁺ vacancies.Finally,well-dispersed hexagonal-like platelets with uniform size and thickness are obtained.更多还原