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.

中文翻译：

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含有镧系元素铒硼碲酸盐玻璃的氧化钴纳米粒子的磁性分析

摘要 我们报告了氧化钴 (Co3O4) 纳米粒子 (NPs) 辅助熔融淬火合成的 Er3+ 掺杂钠镁硼碲酸盐玻璃磁性能的改性。磁性参数的变化归因于 Co3O4 NPs 含量的差异。XRD 图案证实了新掺杂玻璃的非晶性质。玻璃中 Co3O4 NPs 的表面等离子体带显示两个峰，它们对应于尖晶石型氧化钴相和 TEM 图像的特征，表明出现了平均直径为 6.02 ± 0.10 nm 的非球形 Co3O4 NPs。使用振动样品磁力计 (VSM) 进行的磁学研究揭示了硼亚碲酸盐玻璃掺杂的 Er3+ 中 Co 离子的顺磁行为是由嵌入的 Co3O4 NP 贡献的。样品中矩形比的较低值归因于晶粒之间更强的相互作用，这意味着各向同性行为的出现，因此，通过添加 Co3O4 NPs 使它们成为多畴磁性。电子顺磁共振 (EPR) 谱揭示了 g 因子在 4.07-4.22、2.97-3.02、2.11-2.41 范围内的三个突出值。此外，根据 EPR 探测的 Co2+ 离子的氧化态推断，四面体对称性的贡献增加。