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 3 50 K. The substitution of Mn with Fe does not affect markedly the lattice c onstants of the studied compounds, but suppresses strongly the charge order ing. These compounds show semiconductive behavior in the investigated tempe rature range independent of the Fe concentration. Increase of the Fe conten t leads to increasing magnetization at low temperatures, but none of the co mpositions shows a pronounced ferromagnetic component. We connect the obser ved behavior with the bi-strips model of charge ordering as developed for t he Pr1-xCaxMnO3 compounds in the concentrational: range 0.3 less than or eq ual to x < 0.75. (C) 2000 Elsevier Science B.V. All rights reserved.