X-ray diffraction characteristics of new chromitomanganites LaM 3 I CrMnO6 and LaM 3 II CrMnO7.5 (MI = Li, Na; MII = Mg, Ca)

Abstract

LaM 3 I CrMnO6 (MI = Li, Na) and LaM 3 II CrMnO7.5 (MII = Mg, Ca) chromitomanganites were synthesized by ceramic technology from lanthanum oxide, chromium(III) oxide, manganese(III) oxide, lithium carbonate, sodium carbonate, magnesium carbonate, and calcium carbonate. X-ray powder diffraction shows that these compounds crystallize in cubic or tetragonal systems with the following unit cell parameters: for LaLi3CrMnO6 (cubic): a = 10.98 Å, V ○ = 1323.75 Å3, Z = 8, V u.c ○ = 165.47Å3, ρX = 3.64, ρpycn= 3.60 ± 0.04 g/cm3; for LaNa3CrMnO6 (tetragonal): a = 10.96 Å, c = 15.73 Å, V ○ = 1889.51 Å3, Z = 16, V u.c ○ = 118.09 Å3, ρX = 5.77 g/cm3, ρpycn = 5.70 ± 0.07 g/cm3; LaMg3CrMnO7.5 (cubic), a = 10.98 Å, V ○ = 1322.31 Å3, Z = 8, V u.c ○ = 165.29 Å3, ρX = 4.41 g/cm3, ρpycn = 4.35 ± 0.07 g/cm3; and for LaCa3CrMnO7.5 (cubic): a = 10.97 Å, V ○ = 1319.78 Å3, Z = 8, V u.c pO = 164.97 Å3, ρX = 4.89 g/cm3, ρpycn = 4.85 ± 0.05 g/cm3.