Suppression of Ferromagnetic Double Exchange by Vibronic Phase Segregation
Abstract
From Raman spectroscopy, magnetization, and thermal-expansion on the system La2/3(Ca1-xSrx)1/3MnO3, we have been able to provide a quantitative basis for the heterogeneous electronic model for manganites exhibiting colossal magnetoresistance (CMR). We construct a mean-field model that accounts quantitatively for the measured deviation of TC(x) from the TC predicted by de Gennes double exchange in the adiabatic approximation, and predicts the occurrence of a first order transition for a strong coupling regime, in accordance with the experiments. The existence of a temperature interval TC<T<T* where CMR may be found is discussed, in connection with the occurrence of an idealized Griffiths phase.
Cite
@article{arxiv.cond-mat/0509289,
title = {Suppression of Ferromagnetic Double Exchange by Vibronic Phase Segregation},
author = {F. Rivadulla and M. Otero-Leal and A. Espinosa and A. de Andres and C. Ramos and J. Rivas and J. B. Goodenough},
journal= {arXiv preprint arXiv:cond-mat/0509289},
year = {2009}
}
Comments
Replaced with the final version accepted in Physical Review Letters