Correlation between magneto-optical and transport properties of Sr doped manganite films

TL;DR

This study investigates the relationship between magneto-optical and electrical transport properties of Sr-doped manganite films, revealing correlations between MCD spectra features, conductivity types, and temperature-dependent electronic transitions.

Contribution

It provides new insights into how magneto-optical spectra relate to electrical conductivity and electronic structure in Sr-doped manganite films, with detailed spectral analysis and correlation findings.

Findings

High Sr content films become metallic at certain temperatures.

MCD spectral features correlate with conductivity type and temperature.

Different Gaussian lines in MCD spectra correspond to specific electronic transitions.

Abstract

The features of electronic structure of La0.7Sr0.3MnO3, Pr0.8Sr0.2MnO3, and Pr0.6Sr0.4MnO3 polycrystalline films of different thickness have been investigated using magnetic circular dichroism (MCD) in the range of 1.1-4.2 eV. The temperature behavior of the samples electrical resistance were also has been studied. It was found that films with high Sr content (0.3 and 0.4) act as high-temperature semiconductors, while the maximum in the temperature dependences of these films resistivity indicates the transition of the samples to the metallic state at some temperature TM-S, which is different for different sample thickness. The films with the lower Sr content (0.2) act as insulators in the used temperature range. The MCD spectra have been decomposed to the Gaussian-shaped lines, and the temperature dependence of intensity of each line has been analyzed in comparison with temperature dependence of the films magnetization and with their electric conductivity type. Different temperature behavior of the intensity of four specified Gaussian-lines was revealed for semiconductor films. In the case of insulating Pr0.8Sr0.2MnO3 samples, the intensity of three specified Gaussian lines changes with the temperature in the same way as the magnetization changed. It was established that the lanthanide (La, Pr) type does not affect the MCD spectra shape for the films with the same electrical conductivity type. Besides, the correlation between the MCD data of the films and their conductivity type was revealed. Due to the detailed analysis of the specified Gaussian lines with taking into account the well-known in the literature absorption bands, lying outside the studied spectral region, the MCD bands for the studied manganite films have been identified with electronic transitions of a different nature.