Effect of Fe-subsitution on charge ordering in Ca-rich manganites Pr1-xCaxMnO3

Magnetization and resistivity of Pr1-xCaxMn1-yFeyO3 (x = 0.6, 0.7, 0.8; y = 0, 0.05, 0.1, and 0.15) manganites have been investigated between 77 and 350 K. The substitution of Mn with Fe does not affect markedly the lattice constants of the studied compounds, but suppresses strongly the charge ordering. These compounds show semiconductive behavior in the investigated temperature range independent of the Fe concentration. Increase of the Fe content leads to increasing magnetization at low temperatures, but none of the compositions shows a pronounced ferromagnetic component. We connect the observed behavior with the bi-strips model of charge ordering as developed for the Pr1-xCaxMnO3 compounds in the concentrational: range 0.3 less than or equal to x < 0.75. (C) 2000 Elsevier Science B.V. All rights reserved.