Effect of Ba²⁺ Substitution at A-site on Structural, Electrical, and Magnetic Properties of Sm_0.5Ca_0.5MnO₃ Perovskite Manganite

Authors

Nuraina Hanum AbdulRuhim, Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), Perlis Branch, 02600, Arau, Perlis, MalaysiaFollow
Rozilah Rajmi, Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), Perlis Branch, 02600, Arau, Perlis, MalaysiaFollow
Muhammad Zulharmi Taqzim Kamaruzzaman, Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), Perlis Branch, 02600, Arau, Perlis, MalaysiaFollow
Norazila Ibrahim, Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor, MalaysiaFollow

Abstract

Mixed-valence perovskite manganites have attracted considerable attention due to their intriguing properties, such as colossal magnetoresistance and charge ordering (CO). In this study, Sm_0.5Ca_0.5-xBa_xMnO₃ (x = 0, 0.10, 0.20, 0.30, and 0.40) manganites were synthesized via the conventional solid-state reaction method to investigate the effect of Ba²⁺ substitution on their structural, magnetic, and electrical properties. X-ray diffraction patterns confirmed that all samples were single-phase and crystallized in an orthorhombic structure with a Pnma space group. Rietveld refinement indicated an increase in unit cell volume with increasing Ba²⁺ concentration, suggesting the successful substitution of Ba²⁺ at the Ca²⁺ site. Four-point probe resistivity measurements performed over the temperature range of 30–300 K under 0 T and 0.8 T revealed that all Ba-substituted samples remained insulating. Nevertheless, the application of an external magnetic field led to noticeable reduction in resistivity, signifying the presence of magnetoresistance. The increasing Ba²⁺ concentration further reduced resistivity values, indicating the weakening of the CO phase. This effect was attributed to an increase in the average A-site ionic radius, which enhanced the electron bandwidth. Despite the Ba²⁺ substitution, the A-site mismatch cation had a more dominant impact than the increasing bandwidth, resulting in insulating behavior. Magnetic susceptibility measurements showed that Sm_0.5Ca_0.5MnO₃ exhibited paramagnetic behavior with a charge-ordering temperature, T_CO ≈ 270 K. Ba²⁺ substitution (x = 0.10–0.40) led to a weakening in charge ordered state and a reduction in the Néel temperature, T_N.

Keywords

Charge ordered, Electrical resistivity, Magnetoresistance, Manganite, Structural properties

Article Type

Special Issue Article

First Page

108

Last Page

120

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

How to Cite this Article

AbdulRuhim, Nuraina Hanum; Rajmi, Rozilah; Kamaruzzaman, Muhammad Zulharmi Taqzim; and Ibrahim, Norazila (2026) "Effect of Ba²⁺ Substitution at A-site on Structural, Electrical, and Magnetic Properties of Sm_0.5Ca_0.5MnO₃ Perovskite Manganite," Baghdad Science Journal: Vol. 23: Iss. 1, Article 9.
DOI: https://doi.org/10.21123/2411-7986.5142