Dielectric loss

About: Dielectric loss is a research topic. Over the lifetime, 20296 publications have been published within this topic receiving 349254 citations.

Ba0.4Sr0.6TiO3/MgO Composites with Enhanced Energy Storage Density and Low Dielectric Loss for Solid‐State Pulse‐Forming Line

Abstract: (100−x) wt% Ba04Sr06TiO3−x wt% MgO composites (10≤x≤30) were prepared using Ba04Sr06TiO3 powder and nanosized MgO powder (∼60 nm) by a solid-state reaction The energy storage density and dielectric loss were investigated for the purpose of a potential application in solid-state pulse-forming line The results show that Ba04Sr06TiO3/MgO composites exhibit a notably enhanced energy density and low dielectric loss, compared with pure Ba04Sr06TiO3 The enhancement of the energy density is attributed to the notable increase in breakdown strength of the composites and the improvement of dielectric constant stability with regard to electric field In the case of x=30, the samples exhibited a breakdown strength of 331 kV/mm, an energy density of 114 J/cm3, a moderate dielectric constant of 270, and a low dielectric loss of 4 × 10−4

Precise Measurement Method for Temperature Coefficient of Microwave Dielectric Resonator Material

Abstract: A precise measurement method for the temperature coefficient of dielectric resonator material was developed. The error of measurement was decreased from 0.5 ppm/°C to 0.05 ppm/°C compared with the conventional method. This measurement method made techniques for improving stability possible, such as for filters, multiplexer and oscillators.

Ni Flower/MXene-Melamine Foam Derived 3D Magnetic/Conductive Networks for Ultra-Efficient Microwave Absorption and Infrared Stealth

Abstract: The development of multifunctional and efficient electromagnetic wave absorbing materials is a challenging research hotspot. Here, the magnetized Ni flower/MXene hybrids are successfully assembled on the surface of melamine foam (MF) through electrostatic self-assembly and dip-coating adsorption process, realizing the integration of microwave absorption, infrared stealth, and flame retardant. Remarkably, the Ni/MXene-MF achieves a minimum reflection loss (RLmin) of - 62.7 dB with a corresponding effective absorption bandwidth (EAB) of 6.24 GHz at 2 mm and an EAB of 6.88 GHz at 1.8 mm. Strong electromagnetic wave absorption is attributed to the three-dimensional magnetic/conductive networks, which provided excellent impedance matching, dielectric loss, magnetic loss, interface polarization, and multiple attenuations. In addition, the Ni/MXene-MF endows low density, excellent heat insulation, infrared stealth, and flame-retardant functions. This work provided a new development strategy for the design of multifunctional and efficient electromagnetic wave absorbing materials.

Anomalous electrical properties of nanocrystalline Ni–Zn ferrite

Abstract: Nanocrystalline powders of Ni–Zn ferrite (NZFO) having the chemical formula NixZn1−xFe2O4, where x varies as 1, 0.8, 0.6, 0.4, 0.2, and 0, were synthesized by chemical co-precipitation technique. The samples synthesized were characterized by X-ray diffraction (XRD) technique at several stages. As prepared samples at room temperature show absence of Bragg peak indicating that there was no crystalline phase formation of ferrite. The XRD pattern of the samples sintered at 400 °C clearly showed the characteristic Bragg peaks of spinel cubic structure. XRD patterns were further analyzed to calculate the lattice constant, porosity, and jump length of charge carriers. Electrical dc resistivity measurements were carried out with respect to temperature using two probe method. NZFO samples showed abnormal electrical behavior at room temperature. Also abnormal electrical behavior with increase in temperature in the range 600–800 K was observed. Variation of dielectric constant and loss tangent with frequency were studied at room temperature. The electrical and dielectric behavior of the Ni–Zn samples is discussed in the light of literature.

Novel Method for the Fabrication of Flexible Film with Oriented Arrays of Graphene in Poly(vinylidene fluoride-co- hexafluoropropylene) with Low Dielectric Loss

Abstract: Carbon–polymer nanocomposites with good dielectric properties have potential applications in the electronic and electrical industry because of their good mechanical properties and low cost. The morphology, structure, dielectric properties, and mechanical strength of reduced-graphene oxide nanosheet/poly(vinylidene fluoride-co-hexafluoropropylene) nanocomposites (rGO/PVDF-HFP) were investigated. The rGO nanosheets were well dispersed and strongly oriented in the matrix, thanks to the unique spin-assistant preparation process. A dielectric constant of 54 (100 Hz) which was four times higher than that of pure PVDF-HFP was obtained when the concentration of rGO was 0.7 vol % and the dielectric loss was as low as 0.27. The good dielectric performance of the nanocomposites was attributed to the homogeneous dispersion and good alignment of rGO. The shear force provided by spin-coating, the thickness decreasing process, and thickness control were assumed to be key factors in the alignment of rGO nanosheets in the...