Structural effect on colossal magnetoresistivity in manganites: Bond versus band - art. no. 180403

The atomic structure is an important component in the mechanism of the colo ssal magnetoresistance (CMR) phenomenon mainly through the ionic size effec t. In the current understanding, this factor controls the CMR phenomenon by changing the electron bandwidth. while the estimated changes in the bandwi dth appear to be too small to be of significance. By way of the atomic pair distribution function analysis of pulsed neutron diffraction data of model compounds, we suggest that the principal effect of the ionic size is to ch ange the polaron formation energy through the change in the local elastic r esponse.