ABSTRACT: The structure and microwave magnetic properties of Fe powders grounded in argon or acetone and also of Fe-Si-C and amorphous
Fe-Co-Si-C powders mechanically alloyed in argon are studied using X-ray diffraction, Mössbauer spectroscopy, granulometric
and microscopic analyses, magnetostatic measurements, and microwave spectroscopy. The goal of investigation is to determine
the influence of factors (shape, size, and chemical and phase compositions of grains) governing the microwave material parameters
of composites based on these alloys in the frequency range 0.1–3.0 GHz. It is shown that the difference in the grain shape
is the basic reason for the difference in the microwave permeability at low frequencies (3 GHz or lower). At higher frequencies,
the magnetic properties are related to the skin effect and depend largely on the grain size. The differences in the microwave
properties of the composites are not significant and are concealed by the above effects.
Technical Physics 04/2012; 54(4):569-574. · 0.50 Impact Factor
ABSTRACT: Principal factors determining the microwave-absorption material parameters (shape, size, and chemical and phase compositions
of the particles) and their dispersion relations in a range from 0.1 to 3 GHz were determined for composites containing milled
Fe particles as the filling agent. The basic physical mechanisms of the effect of the aforementioned factors were assumed
to be the domain-wall resonance and ferromagnetic resonance.
The Physics of Metals and Metallography 10/2008; 106(5):465-471. · 0.54 Impact Factor
ABSTRACT: The effect of the chemical composition and structural and morphological features of Fe and Fe87Si13 powders milled in an inert atmosphere of Ar and a 3% solution of oleic acid in heptane (H + OA) on the magnetostatic and
microwave properties has been studied in this work. Irrespective of the milling medium, all the samples were nanocrystalline.
The powder particles obtained in Ar have a stonelike shape; those obtained in H + OA, have a platelike (flaky) shape. The
effect of the particle shape manifested itself in the processes of magnetization and in the qualitative and quantitative type
of the frequency dependences of the dielectric permittivity and magnetic permeability in a frequency range from 0.1 to 3 GHz.
The Physics of Metals and Metallography 08/2007; 104(3):248-256. · 0.54 Impact Factor
ABSTRACT: Thin ferromagnetic films are known to exhibit the highest possible microwave permeability of known magnetic materials. Magnetic materials with high microwave magnetic performance are useful for many technical applications. However, bulk rather than planar materials are frequently needed for the applications. Bulk materials with high microwave permeability may be produced as laminated structures of thin ferromagnetic films, possibly patterned. The paper presents experimental data on the microwave permeability of such laminated structures based on Fe films. Possible technical applications of the materials under study include thin wideband radar absorbers and miniaturized patch antennas.
Physics and Engineering of Microwaves, Millimeter and Submillimeter Waves and Workshop on Terahertz Technologies, 2007. MSMW '07. The Sixth International Kharkov Symposium on; 07/2007