Abstract The magnetic properties of artificial opals infiltrated with nickel nanoparticles are studied both experimentally and theoretically. The response of the composite has a dominating ferromagnetic behavior at low magnitude fields (below the saturation region), then it is followed by a dominating diamagnetic one as the intensity of the external applied field is increased. These characteristics are not observed in most cases due to the low magnetic response of the elements involved. Diamagnetism in the artificially synthesized opals was observed, having a negative volume magnetic susceptibility of the order of 10−5. Also theoretical calculations were performed on the basis of the Landau-Lifshitz-Gilbert (LLG) equation, taking into account the diamagnetic response of the host material. Results obtained show the importance of the local magnetic field on the ferromagnetic nanoparticles, as well as the importance of the nature of the magnetic response of SiO2 spheres, which aligns in the opposite direction of the external applied field.

中文翻译：

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局部场效应对蛋白石与 Ni 纳米颗粒的混合铁磁-抗磁响应的影响

摘要 通过实验和理论研究了浸渗有镍纳米颗粒的人造蛋白石的磁性。复合材料的响应在低幅度场（低于饱和区）下具有占主导地位的铁磁行为，然后随着外加场强度的增加，其次是占主导地位的反磁性行为。由于所涉及元素的低磁响应，在大多数情况下不会观察到这些特性。观察到人工合成蛋白石的抗磁性，具有 10-5 数量级的负体积磁化率。还基于 Landau-Lifshitz-Gilbert (LLG) 方程进行了理论计算，同时考虑了主体材料的抗磁响应。