Non-linear effects and Joule heating in I-V curves in manganites

TL;DR

This paper investigates how Joule heating affects the non-linear I-V characteristics in manganite samples, revealing that internal temperature gradients are key to understanding the observed behavior.

Contribution

It introduces an analytical model linking Joule heating to non-linear I-V curves in manganites, emphasizing the role of internal temperature gradients.

Findings

Joule heating significantly influences I-V non-linearity in manganites.

Internal temperature gradients explain the non-linear behavior.

Implications for other colossal magnetoresistance compounds are discussed.

Abstract

We study the influence of the Joule effect on the non-linear behavior of the transport I-V curves in polycrystalline samples of the manganite Pr0.8Ca0.2MnO3 by using the crystalline unit cell parameters as an internal thermometer in X-ray and neutron diffraction. We develop a simple analytical model to estimate the temperature profile in the samples. Under the actual experimental conditions we show that the internal temperature gradient or the difference between the temperature of the sample and that of the thermal bath are at the origin of the non-linearity observed in the I-V curves. Consequences on other compounds with colossal magnetoresistance are also discussed.