Limited local electron-lattice coupling in manganites

TL;DR

This study reveals that in certain manganites, local electron-lattice coupling is weak and does not dominate the complex physics, even in cases with significant magnetoresistance effects.

Contribution

The paper demonstrates that local electron-lattice coupling in manganites is limited, challenging assumptions about its role in their physical properties.

Findings

Superlattice period is locally incommensurate with the parent lattice.

Superlattice orientation shows significant local variations.

Electron-lattice coupling does not overwhelmingly influence manganite physics.

Abstract

(Pr,Ca)MnO3 is the archetypal charge-ordered manganite, but in Pr0.48Ca0.52MnO3 we find (using convergent-beam electron diffraction and dark-field images) that the superlattice period is locally incommensurate with respect to the parent lattice, and that the superlattice orientation possesses significant local variations. This suggests that local electron-lattice coupling never overwhelmingly dominates the rich physics of manganites, even in the most extreme scenarios that produce the largest colossal magnetoresistance effects.