Current localization and Joule self-heating effects in Cr doped Nd0.5Ca0.5MnO3 manganites

TL;DR

This study investigates how direct current affects voltage and temperature in Cr-doped Nd0.5Ca0.5MnO3 manganites, highlighting the roles of current localization and Joule self-heating in phase transitions.

Contribution

It provides experimental evidence and a simple model demonstrating the significance of Joule self-heating and current localization in current-induced phase transitions in manganites.

Findings

Voltage jumps are linked to large temperature increases.

Joule self-heating effects are supported by the model.

Current localization influences phase transition behavior.

Abstract

The effects of dc excitation current on the current-voltage curves of polycrystalline samples of Nd0.5Ca0.5Mn0.96Cr0.04O3 were investigated. The experimental results show that an abrupt jump of the voltage is concomitant with a huge increase in the temperature of the sample. A simple model and estimates for Joule self-heating effects support the experimental data. Moreover, the data strongly suggest that both the current localization in the metallic paths and local Joule self-heating effects are essential ingredients to understand the current-induced phase transition in phase-separated manganites.