Structural and magnetic properties of as-prepared and annealed MgFe₂O₄ nano-powders prepared by auto-combustion method using dl-alanine fuel have been investigated. Nanoparticles with single-crystal electron diffraction patterns are analyzed, and phase purity is confirmed by X-ray diffraction and Raman and infrared spectroscopy. Residual carbon (C), hydrogen (H) and nitrogen (N) content in as-prepared powders is found to reduce by annealing the powders at 900 °C in air. Annealing the as-prepared powders in the range (600–1200 °C) increases the crystallite size from 35 to 46 nm, and increases saturation magnetization to 36 emu/g with low coercivity of ~ 33 Oe. Variations in the magnetic properties are correlated with changes in cation distribution in the octahedral and tetrahedral sites estimated from X-ray diffraction and magnetic studies.

用dl自动燃烧法制备和退火的MgFe ₂ O ₄纳米粉的结构和磁性已研究了丙氨酸燃料。分析具有单晶电子衍射图的纳米粒子，并通过X射线衍射，拉曼光谱和红外光谱确认相纯度。通过在空气中将粉末在900°C下退火，发现所制得粉末中的残留碳（C），氢（H）和氮（N）含量降低。将所制备的粉末在600-1200°C的范围内进行退火，可将微晶尺寸从35 nm增加到46 nm，并将饱和磁化强度提高到36 emu / g，矫顽力约为33 Oe。磁性的变化与通过X射线衍射和磁性研究估计的八面体和四面体部位的阳离子分布变化相关。