Crystal structure and magnetic ordering of manganites La₀.₇Ca₀.₃Mn₁₋ᵧFeᵧO₃

Abstract

The influence of the replacement of Mn ions in the La₀.₇Ca₀.₃Mn₁₋ᵧFeᵧO₃ compounds (0 ≤ y ≤0.09) by another transitional metal, Fe, was studied. The radii of both ions are almost identical, which makes the effect of the transitional metal on the physical properties of manganites more transparent. The crystal structure of three samples (with y = 0, 0.03, 0.09) is studied in the temperature range T = 1.5-300 K by neutron powder diffraction. All investigated samples belong to the orthorhombic space group Pnma (62). It is confirmed that Fe ions occupy the Mn positions in the unit cell. As the Fe concentration increases, the saturation value of the spontaneous magnetic moment and the Curie temperature decrease, but the ground state remains ferromagnetic for 0 ≤ y ≤0.1. The saturation values of the magnetic moments at T = 1.5 K are mFM = 3.72(3), 3.40(3), and 3.27(3)μᵦ/Mn for the samples with an Fe concentration y = 0,0.03, and 0.09, respectively