Complex dielectric and magnetic properties of micro- and nano-size hexagonal ferrites have been studied. Two different measurement techniques have been applied to characterize the samples in the broad frequency range from 1.7 to 120 GHz. It was observed that the constitutive material properties, namely permittivity and permeability, as well as the ferromagnetic resonance frequency of the samples vary with the change in particle dimensions. Based on the results of these measurements, a model for calculating the ferromagnetic resonance frequency of ferrite powders has been derived, which takes into account the size and shape of the particles in the sample. It can be concluded from the size-dependent absorption properties observed in this study that these materials are considered to be tunable millimeter-wave absorbers.

中文翻译：

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用于微波和毫米波器件的纳米尺寸六角铁氧体

已经研究了微米和纳米尺寸六方铁氧体的复杂介电和磁特性。已应用两种不同的测量技术来表征 1.7 至 120 GHz 宽频率范围内的样本。据观察，本构材料特性，即介电常数和磁导率，以及样品的铁磁共振频率随着颗粒尺寸的变化而变化。根据这些测量结果，推导出了计算铁氧体粉末铁磁共振频率的模型，该模型考虑了样品中颗粒的大小和形状。从本研究中观察到的与尺寸相关的吸收特性可以得出结论，这些材料被认为是可调谐的毫米波吸收器。