Investigation of the role of Ag in Pr$_{1-x}$Ag$_x$MnO$_3$ manganites

TL;DR

This study investigates how silver substitution affects the structural, magnetic, and electrical properties of Pr$_{1-x}$Ag$_x$MnO$_3$ manganites, revealing that Ag does not substitute Pr but influences the material's magnetic transition temperature.

Contribution

It provides experimental evidence that Ag does not substitute Pr in the manganite structure and explores how Ag affects magnetic and structural properties.

Findings

Ag$^{+}$ does not substitute Pr$^{3+}$ in the structure.

The Curie temperature increases up to 130 K with Ag addition.

No metal-insulator transition observed in the samples.

Abstract

X-Ray diffraction, ac susceptibility and electrical resistivity measurements were performed in order to investigate the effect of Ag substitution for Pr in the polycrystalline Pr$_{1-x}$Ag$_x$MnO$_3$ (0.0$\leq$x$\leq$0.25) manganites. The XRD results show that the samples crystallize in the O'-orthorhombic structure with a cooperative Jahn-Teller deformation. We give evidence that the Ag$^{+}$ is not substituted at the Pr$^{3+}$ site in the PrMnO$_{3}$ structure. The increase of $T_{C}$ up to 130 K is suggested to be due to further oxidation of manganite grains by the oxygen released from the metallic silver at high temperatures. No metal-insulator transition was observed in the samples.