Temperature Dependence of Microwave Loss, Electronic Transport and Magnetic Parameters in Polycrystalline Perovskite Manganites - Evidence that the Magnetic and the Metal-Insulator Transitions are not Identical

TL;DR

This study investigates how microwave loss, electronic transport, and magnetic properties vary with temperature in polycrystalline perovskite manganites, revealing that magnetic and metal-insulator transitions are distinct and percolative in nature.

Contribution

It provides evidence that magnetic and metal-insulator transitions in manganites are not identical and are driven by percolative processes, challenging previous assumptions.

Findings

Magnetic and metal-insulator transitions occur at different temperatures.

Transitions are percolative in nature.

Microwave loss and transport properties vary distinctly with temperature.

Abstract

Measurements of the variation with temperature of the dc resistivity, ac susceptibility, dc magnetization and microwave loss for several systems of pseudo-cubic manganites reveal that the characteristic temperatures delineated by the various properties can be very The observations further suggest that both the transitions are percolative in nature and therefore there is no a priori reason for them to be identical.