Abstract Effects of magnetic dipole interactions on specific loss power (SLP) for Zn0.3Fe2.7O4/SiO2 core/shell nanoparticles (NPs) with identical magnetic core size and varying non-magnetic shell thicknesses were systematically investigated. In the case of thin silica shell, NPs form chain-like structures due to strong dipole interactions between NPs. The chain formation induces additional shape anisotropy. With increasing thickness of the silica shell, the dipole interaction and therefore the anisotropy induced by the dipole interactions decrease. Meanwhile, the hydrodynamic size of the NPs shows a counterintuitive reduction with increasing shell thickness, also due to the decrease in interactions. The magnetic anisotropy and hydrodynamic size affect the SLP through changes in the Neel and Brownian relaxation rates, leading to different field-dependent SLP values for NPs with thin and thick shells.

中文翻译：

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二氧化硅壳对Zn0.3Fe2.7O4/SiO2纳米颗粒磁热热偶极效应的调谐

摘要 系统地研究了磁偶极相互作用对具有相同磁芯尺寸和不同非磁性壳厚度的 Zn0.3Fe2.7O4/SiO2 核/壳纳米粒子 (NP) 的比损耗功率 (SLP) 的影响。在薄二氧化硅壳的情况下，由于纳米颗粒之间的强偶极相互作用，纳米颗粒形成链状结构。链的形成引起额外的形状各向异性。随着二氧化硅壳厚度的增加，偶极相互作用以及偶极相互作用引起的各向异性降低。同时，纳米颗粒的流体动力学尺寸随着壳厚度的增加而出现违反直觉的减小，这也是由于相互作用的减少。磁各向异性和流体动力学尺寸通过 Neel 和布朗弛豫率的变化影响 SLP，