Abstract:
Detailed investigations of extended x-ray absorption fine structure (EXAFS) associated with the K-edges of Mn and Co have been carried out for LaMn(1-x)Co(x)O(3) +/-delta (0.3 less than or equal to x less than or equal to 1) compounds. It is found that the local structure around Mn is different from that around Co. The distortion in MnO(6) octahedra decreases with the increasing Co content whereas CoO(6) octahedra are undistorted over the entire range of x. The Co-O bond length has been found to decrease with the increase in x. Based on the information about the first shell, the structural anomalies observed in these compounds have been discussed. Complementary information obtained from the XRD and EXAFS studies have been used to explain the behaviour of resistivity in these compounds.
