NaFeO₂ magnetic nanoparticles which are biocompatible and have a relatively high saturation magnetization are considered as promising heat mediators for magnetic hyperthermia applications. In this work, we study aging effects in NaFeO₂ nanoparticles and show that they change their structural and magnetic characteristics over time. As-produced NaFeO₂ nanoparticles synthesized by sol–gel technique have been aged in the ambient atmosphere for 10,000 h. Magnetic properties and aging effect were studied by X-ray diffraction and vibrating sample magnetometry at a temperature ranging from 300 to 500 K. Crystal structure of nanoparticles undergoes essential changes, including an increase of lattice parameter and average coherent block size, and decrease of the microdeformation of crystal lattice. These structural changes affect magnetic parameters of the aged sample. It is shown that saturation magnetization becomes higher and Curie temperature tends to increase as the samples undergo the aging processes.

NaFeO ₂磁性纳米粒子具有生物相容性并具有相对高的饱和磁化强度，被认为是用于磁热疗应用的有前途的热介质。在这项工作中，我们研究了 NaFeO ₂纳米颗粒的老化效应，并表明它们会随着时间的推移而改变其结构和磁性特性。生成的 NaFeO ₂溶胶-凝胶技术合成的纳米颗粒已在环境大气中老化 10,000 小时。在 300 到 500 K 的温度范围内，通过 X 射线衍射和振动样品磁强计研究了磁性和老化效应。纳米粒子的晶体结构发生了本质变化，包括晶格参数和平均相干块尺寸的增加，以及晶格的微变形。这些结构变化会影响老化样品的磁性参数。结果表明，随着样品的老化过程，饱和磁化强度变高，居里温度趋于升高。