Nanosized lithium aluminate (γ-LiAlO2) synthesized by EDTA-citrate complexing method, using different thermal conditions

Lithium aluminate (LiAlO₂) polymorphs have been synthesized by solid-state reaction, but these ceramics usually show certain limitations attributed to the low control on the particle size, morphology and specific surface area. In this sense, different chemical synthesis pathways, citrate precursor among them, have been studied to obtain ultrafine powders exhibiting enhanced textural and morphological features. Synthesis by citrate precursor method would involve the use of alternative chelating agents for the formation of more stable metal-chelate species, such as ethylene-diamine-tetra-acetic acid (EDTA). Thus, the aim of this work was to study the γ-LiAlO₂ synthesis by EDTA-citrate complexing approach to establish the effect of the synthesis route on the structural and microstructural characteristics of the resultant powders. The synthesized ceramic powders were calcined (600-900°C) and characterized by simultaneous TG-DTA, XRD, SEM, TEM and N₂ adsorption-desorption techniques. Crystallization transition process from the precursors to the γ-LiAlO₂ phase is reported. Results show that chemical synthesis by EDTA-citrate complexing method can produce pure and crystalline γ-LiAlO₂ nanoparticles at relative low temperatures (700 ºC). The possible formation mechanism is discussed.