Influence of sintering temperature on resistivity, magnetoresistance and thermopower of La0.67Ca0.33MnO3

TL;DR

This study explores how sintering temperature affects electrical, magnetic, and thermoelectric properties of La0.67Ca0.33MnO3 manganites, revealing correlations between processing conditions and material behavior.

Contribution

It provides a systematic analysis of how varying sintering temperatures influence the physical properties of La0.67Ca0.33MnO3, with detailed characterization and conduction mechanism insights.

Findings

Metal-insulator transition temperature increases with sintering temperature.

Magnetic transition temperature decreases as sintering temperature rises.

Electrical resistivity and thermopower analyzed with scattering and polaron hopping models.

Abstract

A systematic investigation of La0.67Ca0.33MnO3 manganites has been undertaken, mainly to understand the influence of varying crystallite size (nanometer range) on electrical resistivity, magnetic susceptibility and thermoelectric power. The materials were prepared by the sol-gel method of sintering at four different temperatures between 800 and 1100 degrees C. The samples were characterized by X-ray diffraction and data were analyzed using Rietveld refinement. The metal-insulator transition temperatures (TP) are found to increase with increasing sintering temperatures, while the magnetic transition temperatures (TC) decrease. The electrical resistivity and thermoelectric power data at low temperatures (T < TP) have been analyzed by considering various scattering phenomena, while the high temperature (T > TP) data were analyzed with Mott's small polaron hopping conduction mechanisms. PACS Codes: 73.50.Lw, 75.47.Gk, 75.47.Lx