Speaker
Description
Chromium-substituted cobalt ferrite nanoparticles CoCrₓFe₂₋ₓO₄ (0 ≤ x ≤ 2.0) were successfully synthesized via the hydrothermal method. X-ray diffraction (XRD) patterns confirmed the formation of a single-phase cubic spinel structure. Crystallite sizes ranged from 6.6 to 13.7 nm, while lattice parameters decreased from 8.2603 to 8.1974 Å with increasing chromium content. SEM showed uniform grains with discrete boundaries. FTIR spectra exhibited characteristic metal–oxygen stretching vibrations at tetrahedral (615 cm⁻¹) and octahedral (468 cm⁻¹) sites, along with a weak Cr³⁺–O²⁻ band at 499 cm⁻¹, confirming successful cation substitution and bond strengthening. The small remanent magnetization and coercive fields from M-H curves revealed superparamagnetic nature for all samples. The Electron spin resonance (ESR) spectra revealed composition-dependent variations in resonance field (Hres), g-values, and spin relaxation times. The g-value ranged from 4.49 (x = 0) to 2.04 (x = 1.0), indicating a transition toward a more symmetric crystal field and stronger Fe³⁺–Cr³⁺ exchange coupling. These results demonstrate that controlled Cr³⁺ substitution effectively tunes the structural order, local bonding environment, and spin dynamics of cobalt ferrite nanomaterials, making them promising materials for magnetic, electronic, and biomedical applications.
| Apply for student award at which level: | MSc |
|---|---|
| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |