STUDY OF STRUCTURAL, ELECTRICAL TRANSPORT AND MAGNETIC PROPERTIES IN La1-xAgxMnO3 COMPOUNDS.

X-ray diffraction, electrical resistivity and ac susceptibility measurements have been carried out on La1—xAgxMnO3 compounds for x = 0.05 to 0.30. These samples are found to be in single phase form with R&3oline;c space group and with typical lattice parameters a = b = 5.524 Å and c = 13.349 Å for x = 0.05 sample. The Mn­O­Mn bond angles and variance, σ2 are found to increase with doping. Metal-insulator transitions in the temperature range 254 to 259 K have been observed. These materials exhibit paramagnetic to ferromagnetic transitions in the vicinity of metal-insulator transition temperatures. The paramagnetic susceptibility could be analyzed using Curie­Weiss law. All the above samples exhibit colossal magneto-resistivity and its maximum value is found to be 73% for x = 0.15 sample at 50 kOe magnetic field. [ABSTRACT FROM AUTHOR]