Mechanosynthesis of Ca-Xa-(1-X))MnO-3 (0

摘要

Reactive ball milling was employed to produce nanocrystalline calcium doped lanthanum manganites (CDLM), Ca-xLa-1-xMnO-3, for different milling times and varying the content of calcium from x=0 to x=0.7 with increments of 0.1. The aim of this work is to study the relationship between the content of calcium, the crystalline structure, and the mixed ionic-electronic conductivity. Powders of Mn-2O-3, La-2O-3, and CaO, mixed in the stoichiometric ratio, were used as raw materials. The mechanosynthesis was carried out using a high energy shaker mixer/mill. X-ray powder diffraction and Rietveld refinement were used to elucidate the crystalline structure as a function of calcium content. Electrical resistivity of the compacted and sintered powders was acquired using a milli DC ohm-meter. Results showed that it is possible to obtain Ca-xLa-1-xMnO-3 by mechanosynthesis. The mixed ionic-electronic conductivity decreases with the Ca doped level. The best conductivity is presented for the Ca-0.1La-0.9MnO-3 composition.