Abstract
The amplitude and temperature , where the colossal magnetoresistance (CMR) response of manganites are maximum, are found to be controlled by the radius of the lanthanide which modifies the bending of the Mn-O-Mn bond. Increasing the bond distortion lowers and enhances . Enhanced CMR arises from (1) a shift to lower temperatures of , (2) a reduced mobility of the doping holes, and (3) an increase of the coupling between itinerant and localized electrons. The resistivity follows an law and the parameter is also tuned by the Mn-O-Mn bond angle. The narrowing of the electronic bandwidth is the fundamental parameter controlling the observed CMR.
- Received 19 June 1995
DOI:https://doi.org/10.1103/PhysRevLett.76.1122
©1996 American Physical Society