• P KIDKHUNTHOD

Articles written in Bulletin of Materials Science

• Local structure analysis of $B$O$_6$ ($B = {\rm Fe, Cu}$) octahedron correlated with the magnetic properties of Cu-doped Ba$_{0.5}$Sr$_{0.5}$FeO$_{3–\delta}$

Perovskite-based Ba$_{0.5}$Sr$_{0.5}$Fe$_{1–x}$Cu$_x$O$_{3–\delta}$ (BSFCO-$x$, $x = 0–0.2$) was synthesized by sol–gel self-combustionmethod. The crystallinity was evaluated through X-ray diffraction, besides further local structure analysis, using X-ray absorption spectroscopy (XAS) showed a cubic symmetry for $x = 0.05$; 0.10, which was tetragonal at higher values, $x =0.15; 0.20$. XAS analysis predicted the oxidation state (OS) of Cu to be a mixture of 3$+$ and 2$+$, while Fe includes 3$+$ and 4$+$. Conversely, the OS of Fe and Cu in the octahedron site influence the number of an unpair electron that determine the magnetic properties of perovskite. In addition, the magnetization for Ba$_{0.5}$Sr$_{0.5}$FeO$_{3–\delta}$ is 0.172 emu g$^{-1}$, originating from the ferromagnetic ordering Fe$^{3+}$($t_{2g}^3 e_g^2$)–O(2p)–Fe$^{4+}$($t_{2g}^3 e_g^1$) interaction. This effect increase, due to the presence of oxygen vacancy in BSFCO-0.05, which weakens the $d–p$ interaction of Fe-O, while the generation of higher Cu doping to increase the amount of Fe$^{4+}$ leads to a decline in Cu$^{3+}$. Therefore, Cu doping is confirmed to play a role in the paramagnetic–ferromagnetic transition.

• # Bulletin of Materials Science

Volume 43, 2020
All articles
Continuous Article Publishing mode

• # Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020