Naive model from 1970th applied to CMR manganites: it seems to work

TL;DR

This paper applies a simplified 1970s model to analyze colossal magnetoresistance manganites, showing that the Weiss exchange field derived from experimental data aligns with local magnetization, supporting the model's validity.

Contribution

It demonstrates that a naive, classical semiconductor model from the 1970s can effectively describe CMR manganites, using minimal parameters and aligning with experimental magnetization data.

Findings

The Weiss field correlates with temperature and magnetic field similarly to local magnetization.

The model successfully explains resistivity changes in CMR manganites.

Minimal adjustable parameters suffice for the model to fit experimental data.

Abstract

Existing experimental data for various colossal magnetoresistance manganites have been examined employing an ovesimplified model that roots in 1970th. This model considers a classical semiconductor where conducting bands are affected by the strong Weiss exchange field that arises from the magnetic order in the substance. The field--caused shifts of the conducting bands results in the change in the number of thermally activated carriers, and this change is presumed to be responsible for the resistivity dependences on temperature and magnetic field and for the CMR itself. Employing this model we calculate this hypothetical Weiss field from the experimental data for various CMR manganites employing minimal set of the adjustable parameters, namely two. The obtained Weiss field behaves with temperature and external field similarly to the local magnetization, its supposed source, hence supporting the model.