On the effects of the magnetic field and the isotopic substitution upon the infrared absorption of manganites

TL;DR

This study investigates how magnetic fields and oxygen isotope substitution influence the phase diagram, electron-phonon interactions, and infrared absorption in manganites, revealing strong correlations with conductivity and magnetic properties.

Contribution

It introduces a variational approach that incorporates electron-phonon and magnetic interactions to analyze effects of magnetic field and isotope substitution in manganites.

Findings

Lattice displacements strongly correlate with conductivity and magnetic properties.

Infrared absorption spectra are highly sensitive to external parameters near phase boundaries.

Magnetic field and isotope substitution significantly alter the phase diagram and electron-phonon correlations.

Abstract

Employing a variational approach that takes into account electron-phonon and magnetic interactions in $La_{1-x}A_xMnO_3$ perovskites with $0<x<0.5$, the effects of the magnetic field and the oxygen isotope substitution on the phase diagram, the electron-phonon correlation function and the infrared absorption at $x=0.3$ are studied. The lattice displacements show a strong correlation with the conductivity and the magnetic properties of the system. Then the conductivity spectra are characterized by a marked sensitivity to the external parameters near the phase boundary.