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

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$\le$x$\le$0.25) manganites. The XRD results show that the samples crystallize in the O'-orthorhombic structure with a cooperative Jahn-Teller deformation. We give evidence that the Ag${}^{+}$ 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.

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