In this report, we adopted an auto-combustion method to synthesize polycrystalline magnetite (Fe₃O₄) and magnesium ferrites (MgFe₂O₄) nanoparticles. The synthesized nanoparticles were characterized using techniques such as X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FTIR), Vibration sample magnetometer (VSM) and photoluminescence (PL) spectroscopy. X-ray diffraction profiles of all the synthesized nanoparticles [Fe₃O₄ (500 °C): FO NPs, MgFe₂O₄ (500 °C): MFO1 NPs and MgFe₂O₄ (700 °C): MFO2 NPs] confirmed phase pure crystallinity without any secondary phases such as FeO and Fe₂O₃, etc. The implementation of Rietveld refinement determined the cubic crystal symmetry with space group \(Fd\stackrel{-}{3}m\) for all the synthesized nanoparticles. FE-SEM micrographs depicted the pseudo-spherical morphology with an average grain size of 26.18 nm, 51.6 nm, and 69.68 nm for FO NPs, MFO1 NPs, and MFO2 NPs, respectively. FTIR spectra illustrated the appearance of peaks at 1645 cm⁻¹ and 1345 cm⁻¹ which attributes to metal ions (Fe³⁺/Mg²⁺). Photoluminescence spectra of synthesized nanoparticles displayed the emission wavelength in a range of 508–521 nm. The values of saturation magnetization for FO NPs, MFO1 NPs, and MFO2 NPs were found to be 34.2 emu/g, 15.3 emu/g, and 28.8 emu/g, respectively. The magnetization of MgFe₂O₄ nanoparticles increased with increasing calcination temperature (500–700 °C) so as the grain size. It indicated that Mg substitution at A-site of AB₂O₄-type (MgFe₂O₄) spinel ferrite not only gave the phase pure crystal structure but also compete with the magnetic properties of Fe₃O₄ with increasing calcination temperature. MgFe₂O₄ nanoparticles (calcined at 700 °C) depicted superparamagnetic behavior and can be utilized as a drug delivery agent for biomedical applications.

在本报告中，我们采用了自动燃烧方法来合成多晶磁铁矿（Fe ₃ O ₄）和铁氧体镁（MgFe ₂ O ₄）纳米颗粒。使用诸如X射线衍射（XRD），场发射扫描电子显微镜（FE-SEM），傅立叶变换红外光谱（FTIR），振动样品磁力计（VSM）和光致发光（PL）光谱的技术对合成的纳米颗粒进行表征。所有合成的纳米颗粒的X射线衍射图[Fe ₃ O ₄（500°C）：FO NPs，MgFe ₂ O ₄（500°C）：MFO1 NPs和MgFe ₂ O ₄（700°C）：MFO2 NPs]证实了相纯结晶度，没有任何次级相，如FeO和Fe ₂ O ₃等。Rietveld精炼的实施确定了空间群\（Fd \ stackrel {-} { 3} m \）的所有合成纳米粒子。FE-SEM显微照片描绘了伪球形的形态，FO NP，MFO1 NP和MFO2 NP的平均晶粒尺寸分别为26.18 nm，51.6 nm和69.68 nm。FTIR光谱显示了出现在1645 cm ^-1和1345 cm ^-1处的峰，这归因于金属离子（Fe ³⁺ / Mg ²⁺）。合成的纳米颗粒的光致发光光谱显示其发射波长在508-521 nm范围内。发现FO NP，MFO1 NP和MFO2 NP的饱和磁化强度分别为34.2 emu / g，15.3 emu / g和28.8 emu / g。MgFe ₂ O ₄纳米颗粒的磁化强度随着煅烧温度（500–700°C）的增加而增加，随晶粒尺寸的增加而增加。结果表明，随着焙烧温度的升高，AB ₂ O ₄型（MgFe ₂ O ₄）尖晶石型铁素体的A位上的Mg取代不仅赋予了相纯晶体结构，而且还与Fe ₃ O ₄的磁性能竞争。镁铁₂O ₄纳米颗粒（在700°C下煅烧）表现出超顺磁性行为，可以用作生物医学应用中的药物递送剂。