Anomalous magnetic and transport properties of La(0.8-x)Eu(x)Sr0.2MnO3 (0.04 l.e. x l.e. 0.36) compounds

TL;DR

This study investigates the magnetic and transport anomalies in La(0.8-x)Eu(x)Sr0.2MnO3 compounds, revealing non-monotonic changes in Curie temperature and resistivity with Eu doping, linked to structural disorder and electronic phase segregation.

Contribution

It provides new insights into how Eu doping influences magnetic and transport properties, highlighting the role of structural disorder and phase segregation in these materials.

Findings

Curie temperature decreases then increases with Eu doping

Resistivity peaks at intermediate Eu concentrations

Two magnetoresistance peaks correlate with magnetic transitions

Abstract

Anomalous magnetic and transport properties observed in the La0.8-xEuxSr0.2MnO3 (0.04 l.e x l.e. 0.36) compounds are presented in this paper. The Curie temperature (TC) decreases from 260 K for x = 0.04 to 188 K for x = 0.16 and surprisingly thereafter increases for higher Eu concentrations (x > 0.16) and becomes nearly constant ~230 K. Resistivity increases with Eu concentration up to x = 0.16 but decreases for higher Eu concentration (x > 0.16). In the magnetoresistance data, in addition to a peak corresponding to the insulator-metal transition at (TI-M1), a second peak is also observed at a relatively lower temperature, (TI-M2). Both TI-M1 and TI-M2 follow the same trend as TC. The unique variation of TC and magnetoresistance is explained on the basis of structure and disorder correlated to microscopic electronic phase segregation. The studies with the existing studies also point to the universibility of this consideration.