SAIP2025

Comparative Analysis of Co-precipitation and Sol-Gel Derived Sm₂Ni₂O₅ Nanoparticles: Structural, Chemical, Thermodynamic, and Magnetic Properties

8 Jul 2025, 14:40

20m

Solomon Mahlangu House (University of the Witwatersrand, Johannesburg)

Oral Presentation Track A - Physics of Condensed Matter and Materials Physics of Condensed Matter and Materials 2

Speaker

Khethiwe Cele (Rare Earth-Based Oxides and Nano Group, Department of Physics, University of Johannesburg, Cnr Kingsway Avenue and University Road, Auckland Park 2006, South Africa)

Description

In this study, crystalline Sm₂Ni₂O₅ nanoparticles (SNONPs) were synthesized using both the co-precipitation and sol-gel methods to compare the influence of the synthesis’ method on the structural, chemical, thermodynamic, and magnetic properties of the material. X-ray diffraction (XRD) analysis revealed that samples from both methods crystallized in an orthorhombic structure of the Ima2 space group after annealing at 800 °C. SEM images revealed that co-precipitated samples had spherical particles, while sol-gel samples exhibited irregular, textured morphologies. EDS results showed comparable elemental compositions in both samples, with slight variations in oxygen content. Specific heat (Cp) measurements under a 0.5 T magnetic field revealed a ferromagnetic transition at ~42.3 K in both cases. Additionally, a sharp increase in Cp below 150 K and a deviation in Cp/T below 9 K suggested the onset of spin ordering due to magnetic interactions between Sm³⁺ (4f) and the mixed oxidation states of Ni (Ni²⁺ and Ni³⁺). These findings highlight the impact of synthesis route on the crystallinity and consequently the chemical, thermodynamic and magnetic behavior of SNONPs, suggesting its potential for spintronic and low-temperature magnetic applications.