We studied Zn0.75Ni0.25Fe 2O4 magnetic nanoparticles before and after plasma treatment by employing X-ray diffraction, magnetic measurements, hyperthermia measurements using the mag-neTherm device, and Mossbauer spectroscopy. The Mossbauer spectra of Zn0.75Ni0.25Fe 2O4 were recorded at various temperatures from 4.2 to 295 K. The Mossbauer spectra for temperatures below the superparamagnetic transition temperature exhibited two sextets ascribed to tetrahedral and octahedral sites. Furthermore, the spectra demonstrated superparamagnetic behavior, as indicated by the doublet with zero hyperfine field at 295 K. The Mossbauer spectra exhibited line broadening with increasing temperature, indicating superparamagnetic relaxation. The temperature dependence of the anisotropy energy was calculated based on the relaxation frequency.

中文翻译：

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Zn0.75Ni0.25Fe2O4 中的超顺磁性超精细弛豫

我们通过使用 X 射线衍射、磁测量、使用磁力设备的热疗测量和穆斯堡尔光谱研究了等离子体处理前后的 Zn0.75Ni0.25Fe 2O4 磁性纳米粒子。Zn0.75Ni0.25Fe 2O4 的穆斯堡尔谱是在 4.2 到 295 K 的不同温度下记录的。低于超顺磁性转变温度的穆斯堡尔谱显示出两个六重谱，分别归属于四面体和八面体位点。此外，光谱表现出超顺磁行为，如在 295 K 处具有零超精细场的双峰所示。穆斯堡尔谱表现出随温度升高的谱线加宽，表明超顺磁弛豫。基于弛豫频率计算各向异性能量的温度依赖性。