Charge ordering in crystals of Pr1−x Sr x MnO3 (x = 0.22, 0.24) ferromagnetic manganites

The structural and magnetic states of Pr1−x Sr x MnO3 (x = 0.22, 0.24) manganite crystals were studied over a wide temperature range. Measurements of the magnetic susceptibility and electrical resistivity demonstrated that these manganites belong to the class of ferromagnetic semiconductors. Thermal neutron elastic scattering patterns revealed that, in the temperature range 4.2–350 K, the manganites have an orthorhombic structure (space group Pnma) with a well-pronounced cooperative Jahn-Teller effect. Major emphasis was placed on the nuclear magnetic superstructure with a wave vector q = (2π/2a, 0, 2π/2c). It was shown that this superstructure suggests 1/4-type charge ordering in the manganites under investigation.