The Influence of Mechanical Processing of Initial Reagents on Structural and Electrical Properties of LiFeO2 Ceramics

The effect of mechanical processing of a mixture of initial Fe2O3 and Li2CO3 powders on the structure and electrical properties of lithium ferrite ceramics of LiFeO2 composition is studied. Mechanical processing is carried out in an AGO-2S ball mill for 60 min with a cup rotation speed of 2220 rpm. Sintering of ceramic samples is carried out in a laboratory furnace at 1050°C for 1 h. The X-ray diffraction analysis data show that the introduction of the mechanical powder processing procedure leads to a decrease in the concentration of the α-LiFeO2 phase in ferrite ceramics from 97.9 to 93.9 wt %, as well as to an increase in the secondary LiFe5O8 phase from 2.1 to 6.1 wt %. During sintering, a more homogeneous and fine-pore structure of the samples is formed in this case. On the basis of temperature dependences of the specific electrical conductivity of the samples, it is established that changes in electrical resistance are related to both the microstructure and the adsorption-desorption processes (depending on temperature) of gas from the surrounding atmosphere into the ferrite ceramics. The obtained ferrite ceramics are of interest for their further use as an adsorbate, for example, of carbon monoxide.