Investigation of nanocrystalline phases in Li–La–Fe–O system formed by the decomposition of acetylacetonato complexes

Abstract

Applying a new synthesis route based on the thermal decomposition of a mixture acetylacetonato complexes, Li(AA) , La(AA) 3 and Fe(AA) 3, Li, La ferrite (Li 0.5La 0.08Fe 2.42O 4) was formed. The element analysis performed by ICP technique and the Rietveld refinement data indicate that the sample is composed of three phases: Li 0.5La 0.08Fe 2.42O 4 (69%, SG P4 332, a = 8.3445(3) Å) , La 0.14Fe 3O 4 (16%, SG F d 3 ¯ m , a = 8.403(1) Å) and LiFeO 2 (15%, SG F m 3 ¯ m , a = 4.2291(8) Å). A partial substitution Fe 3+ → La 3+ in Li ferrite and La insertion at 16c site in Fe 3O 4 occur at low concentrations. A partial cation ordering at 4b and 12d octahedral sites in Li 0.5La 0.08Fe 2.42O 4 was noticed. TEM micrograph shows that the nanoparticles are spherically shaped and that the particle distribution is in the range between 7 and 33 nm. The sample exhibits superparamagnetic behavior, thus the composite has potential industrial applications.