Magnetic analysis of cobalt oxide nanoparticles comprised boro-tellurite glass with erbium lanthanide

Abstract We report the cobalt oxide (Co3O4) nanoparticles (NPs) assisted modifications of magnetic properties of melt-quench synthesized Er3+ doped sodium magnesium boro-tellurite glass. The changes in magnetic parameters are attributed to the difference in the content of Co3O4 NPs. XRD pattern confirmed the amorphous nature of the newly doped glasses. Surface plasmon band of Co3O4 NPs in the glass revealed two peaks which are corresponded to the characteristic of spinel-type cobalt oxide phase and TEM images manifest the occurrence of non-spherical Co3O4 NPs having an average diameter 6.02± 0.10 nm. Magnetic study using Vibrating Sample Magnetometer (VSM) revealed the paramagnetic behavior of Co ion in boro-tellurite glass doped Er3+ contributes by the embedded Co3O4 NPs. The lower value of squareness ratio in the sample is attributed by stronger interactions among grains implying the appearance of isotropic behavior, hence, making them as a multi-domain magnetic with the addition of Co3O4 NPs. Electron Paramagnetic Resonance (EPR) spectra revealed three prominent value of g factor at ranges of 4.07∼4.22, 2.97∼3.02, 2.11∼2.41. Furthermore, the tetrahedral symmetry contribution is increased as inferred from the oxidation states of Co2+ ions probed by EPR.