TY - JOUR
T1 - Crystal structure and mixed ionic-electronic conductivity of La 1-xCa xMnO 3 (0 ≤ x ≤ 0.8) produced by mechanosynthesis
AU - Sánchez-De Jesús, F.
AU - Cortés-Escobedo, C. A.
AU - Bolarín-Miró, A. M.
AU - Lira-Hernández, A.
AU - Torres-Villaseñor, G.
N1 - Funding Information:
This project was financially supported by the National Science and Technology Council of Mexico (CONACyT) under the grant numbers 129910 and 130413 . The authors are grateful for the assistance with X-ray diffraction from Adriana Tejeda Cruz from the Institute of Materials of UNAM.
PY - 2012/4
Y1 - 2012/4
N2 - The aim of this work was to study the relationship between the crystalline structure, the mixed ionic-electronic conductivity and the calcium content in calcium-doped lanthanum manganites (CLM, La 1-xCa xMnO 3) synthesized by reactive ball milling. Mechanosynthesis was employed to produce nanocrystalline CLM with varying calcium content (x = 0-0.8 in increments of 0.1). 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 determine the crystalline structure as a function of calcium content. The four-point probe resistivity test was used to measure the electrical resistivity of the compacted and sintered powders using a DC milli-ohm meter. The results showed that the substitution of the La 3+ ion by the Ca 2+ ion during mechanosynthesis only changed the lattice parameters but not the orthorhombic Pnma structure. The mixed ionic-electronic conductivity increased with the Ca 2+ content. The best conductivity was observed for the composition of La 0.2Ca 0.8MnO 3.
AB - The aim of this work was to study the relationship between the crystalline structure, the mixed ionic-electronic conductivity and the calcium content in calcium-doped lanthanum manganites (CLM, La 1-xCa xMnO 3) synthesized by reactive ball milling. Mechanosynthesis was employed to produce nanocrystalline CLM with varying calcium content (x = 0-0.8 in increments of 0.1). 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 determine the crystalline structure as a function of calcium content. The four-point probe resistivity test was used to measure the electrical resistivity of the compacted and sintered powders using a DC milli-ohm meter. The results showed that the substitution of the La 3+ ion by the Ca 2+ ion during mechanosynthesis only changed the lattice parameters but not the orthorhombic Pnma structure. The mixed ionic-electronic conductivity increased with the Ca 2+ content. The best conductivity was observed for the composition of La 0.2Ca 0.8MnO 3.
KW - Crystal structure
KW - Lanthanum manganites
KW - Mechanosynthesis
KW - Mixed ionic-electronic conductivity
KW - X-ray diffraction
UR - http://www.scopus.com/inward/record.url?scp=84857047374&partnerID=8YFLogxK
U2 - 10.1016/j.ceramint.2011.10.055
DO - 10.1016/j.ceramint.2011.10.055
M3 - Artículo
SN - 0272-8842
VL - 38
SP - 2139
EP - 2144
JO - Ceramics International
JF - Ceramics International
IS - 3
ER -