MOSSBAUER STUDIES OF NEW CMR COMPOUNDS (LA1-XSNX)(2)(MN0.985FE0.015)(2)O-Y

Mossbauer spectra of (La1-xSnx)(2)(Mn0.985Fe0.015)(2)O-y (x = 0.2, 0.3 , 0.4 and 0.5) from room temperature to 4.2 K have been studied; in ad dition X-ray diffraction patterns at room temperature have been obtain ed. The results show that the phase compositions of (La1-xSnx)(2)(Mn0. 985Fe0.015)(2)O-y are strongly dependent on the Sn concentrations and on the heat treatment. The manganites with a: = 0.2, 0.3 and 0.4 after annealing in air at 1200 degrees C appear to consist of two phases, A BO(3) and A(2)B(2)O(7) Their Mossbauer spectra are paramagnetic double ts at room temperature that become sextets at T similar to 230 K and s imilar to 60 K. The ABO(3) phase appears to be the source of the CMR i n manganite (La0.7Sn0.3)(2)(Mn0.985Fe0.015)(2)O-y.