Intergranular insulated Fe-6.5 wt% Si/SiO2 composite compacts with tunable insulating layer thickness for low core loss applications

RSC Advances ◽  
2015 ◽  
Vol 5 (82) ◽  
pp. 67031-67040 ◽  
Author(s):  
Z. Y. Wu ◽  
X. A. Fan ◽  
G. Q. Li ◽  
J. Wang ◽  
Z. H. Gan
Keyword(s):  
Layer Thickness ◽  
Core Loss ◽  
Insulating Layer ◽  
Teos Concentration

Variations of microstructure and eletromagnetic properities with TEOS concentration for intergranular insulated Fe-6.5 wt% Si/SiO2 composite compacts.

Preparation and Magnetic Properties of Fe@SiO2 Soft Magnetic Composites

2020 ◽  
Vol 993 ◽  
pp. 638-645
Author(s):  
Shuai Feng ◽  
Yan An ◽  
Zong Xiang Wang ◽  
Kai Sun ◽  
Run Hua Fan
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Core Loss ◽  
Low Frequency ◽  
Magnetic Flux Density ◽  
Iron Particles ◽  
Soft Magnetic ◽  
Magnetic Composites ◽  
Insulating Layer ◽  
Iron Powders

In this work, the insulating SiO2 was coated successfully on the surface of reduced iron particles by a sol-gel method to decrease the core loss at low frequency. The scanning electron microscope images and elements analysis confirm that the surface of iron powders particles were covered by a thin insulating layer in the form of uniform core-shell structure. The samples were annealed at 400 °C in N2 atmosphere to obtain better magnetic properties. The annealed SMCs with 10 mL/h dropping rate of TEOS have optimum magnetic properties with low core loss Ps of 280.89 W/kg and high saturation magnetic flux density Bs of 1.038 T at 1000 Hz.

Study of Electronic Structure In Ni3Fe/Al2O3/Ni3Fe Magnetic Tunnel Junction with Various Ferromagnetic Layer Thicknesses

2005 ◽  
Vol 475-479 ◽  
pp. 3909-3914
Author(s):  
Yuan Zhou ◽  
Xiao Fang Bi ◽  
Jia Xiang Shang ◽  
Hui Bin Xu
Keyword(s):  
Electronic Structure ◽  
Layer Thickness ◽  
Spin Polarization ◽  
Tunnel Junction ◽  
Great Influence ◽  
Ferromagnetic Layer ◽  
Magnetic Tunnel Junction ◽  
Local Spin Density Approximation ◽  
Insulating Layer ◽  
Maximum Value

A series models of Ni3Fe/Al2O3/Ni3Fe magnetic tunnel junction with Al-terminated interfaces have been established for investigating the influence of ferromagnetic layer thickness on the electronic structure, employing first-principle methods based on local spin-density approximation theory. The spin polarization of the interfacial Ni3Fe monolayer shows a maximum value as the thickness of ferromagnetic layer increases. The Al monolayers at the ferromagnetic/insulating interface and the O monolayer in the interior of insulating layer are also studied in terms of the change of spin polarization with the ferromagnetic layer thickness. In addition, we have found that the structure of Ni3Fe monolayer has a great influence on the spin polarization.

Quantum Size Effect of 2DEG Confined Within BaTiO3/SrTiO3:Nb Superlattices

2007 ◽  
Vol 1044 ◽  
Author(s):  
Yuki Nakanishi ◽  
Hiromichi Ohta ◽  
Teruyasu Mizoguchi ◽  
Yuichi Ikuhara ◽  
Kunihito Koumoto
Keyword(s):  
Size Effect ◽  
Seebeck Coefficient ◽  
Layer Thickness ◽  
Film Growth ◽  
Quantum Size Effect ◽  
Single Crystal Substrate ◽  
Cross Sectional ◽  
Insulating Layer ◽  
Quantum Size ◽  
Unit Cells

AbstractVery recently, we have found that the high density 2DEG (ne ∼1021 cm−3), which is confined within a unit cell layer thickness of SrTiO3, exhibits unusually large Seebeck coefficient (S2DEG/Sbulk ∼5)[1]. In the optimum, extremely high ZT2DEG of ∼2.4 can be obtained at room temperature, while the effective ZTeff. was only ∼0.24 because 9 unit cells of electrically insulating SrTiO3 layers were used to fabricate the 2DEG structure. Thus, high ZTeff can be realized if the insulating layer thickness is reduced significantly. We selected BaTiO3∼SrTiO3:Nb superlattice to reduce insulating layer thickness because dielectric constant of BaTiO3 is one order of magnitude large (∼3,000) as compared to that of SrTiO3 (∼300). We expected that the conduction electrons can be confined much strongly in the SrTiO3:Nb layer by sandwiching between highly dielectric BaTiO3 layers. As a result, we clarified that the critical BaTiO3 layer thickness is 1.2 nm, significantly small as compared to SrTiO3 layer (4 nm). The BaTiO3/SrTiO3:Nb superlattice films were fabricated by a pulsed laser deposition (PLD) method on (001)-face of LaAlO3 single crystal substrate at 900°C. During the film growth, we monitored RHEED intensity oscillation to control layer thickness precisely. Out-of-plane high-resolution X-ray diffraction measurements and cross sectional HAADF-STEM observations revealed that the resultant films were high quality BaTiO3/SrTiO3:Nb superlattice. Hall mobility of the SrTiO3:Nb layer was 0.4 cm2·V−1·s−1, while that of superlattice decreased gradually with increasing BaTiO3 layer thickness most likely due to that intra layer diffusion of Ba2+ ion occurred between BaTiO3 and SrTiO3:Nb layers[2], which was clearly observed by the EELS mapping. Seebeck coefficient |S|300K of SrTiO3:Nb layer was 57 μV·K−1, which corresponds carrier concentration ne of 5×1021 cm−3. The |S|300K value became large with decreasing the SrTiO3:Nb layer thickness (dSrTiO3:Nb) and it reached 305 μV·K−1, which is approximately 5 times larger than that of SrTiO3:Nb bulk. The slope of log |S|- log dSrTiO3:Nb plots was 1/2, suggesting that quantum size effect occurred. Critical BaTiO3 layer thickness for the quantum confinement of the electrons was 1.2 nm (3 unit cells of BaTiO3), which is significantly small as compared to SrTiO3 (4 nm). Thus, BaTiO3/SrTiO3:Nb superlattice would be a promising candidate to realize high ZTeff.

FILM THICKNESS INFLUENCES ON THE THERMOELECTRIC PROPERTIES OF NiCr/NiSi THIN FILM THERMOCOUPLES

2013 ◽  
Vol 27 (14) ◽  
pp. 1350103 ◽  
Author(s):  
Y. Z. CHEN ◽  
H. C. JIANG ◽  
W. L. ZHANG ◽  
X. Z. LIU ◽  
S. W. JIANG
Keyword(s):  
Thin Film ◽  
Layer Thickness ◽  
Thermoelectric Properties ◽  
Layer Structure ◽  
Protective Layer ◽  
Electron Beam Evaporation ◽  
Insulating Layer ◽  
Bond Layer ◽  
Thin Film Thermocouples ◽  
The Stability

NiCr / NiSi thin film thermocouples (TFTCs) with a multi-layer structure were fabricated on Ni -based superalloy substrates (95 mm × 35 mm × 2 mm) by magnetron sputtering and electron beam evaporation. The five-layer structure is composed of NiCrAlY buffer layer (2 μm), thermally grown Al 2 O 3 bond layer (200 nm), Al 2 O 3 insulating layer (10 μm), NiCr / NiSi TFTCs (1 μm), and Al 2 O 3 protective layer (500 nm). Influences of thermocouple layer thickness on thermoelectric properties were investigated. Seebeck coefficient of the samples with the increase in thermocouple layer thickness from 0.5 μm to 1 μm increased from 27.8 μV/°C to 33.8 μV/°C, but exhibited almost no change with further increase in thermocouple layer thickness from 1 μm to 2 μm. Dependence on temperature of the thermal electromotive force of the samples almost followed standard thermocouple characteristic curves when the thickness of the thermocouple layer was 1 μm and 2 μm. Sensitive coefficient K of the samples increased greatly with the increase in thickness of the thermocouple layer from 0.5 μm to 1 μm, but decreased insignificantly with the increase in thermocouple layer thickness from 1 μm to 2 μm, and continuously decreased with the increase in temperature. The sensitive coefficient and the stability of NiCr / NiSi TFTCs were both improved after annealing at 600°C.

scholarly journals Enhanced Magnetic Properties of FeSiAl Soft Magnetic Composites Prepared by Utilizing PSA as Resin Insulating Layer

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1350
Author(s):  
Hao Lu ◽  
Yaqiang Dong ◽  
Xincai Liu ◽  
Zhonghao Liu ◽  
Yue Wu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Electrical Resistivity ◽  
High Temperatures ◽  
Core Loss ◽  
Soft Magnetic ◽  
Magnetic Composites ◽  
Thermal Stabilities ◽  
Insulating Layer ◽  
High Electrical Resistivity ◽  
Soft Magnetic Composites

Thermosetting organic resins are widely applied as insulating coatings for soft magnetic powder cores (SMPCs) because of their high electrical resistivity. However, their poor thermal stability and thermal decomposition lead to a decrease in electrical resistivity, thus limiting the annealing temperature of SMPCs. The large amount of internal stress generated by soft magnetic composites during pressing must be mitigated at high temperatures; therefore, it is especially important to find organic resins with excellent thermal stabilities. In this study, we prepared SMPCs using poly-silicon-containing arylacetylene resin, an organic resin resistant to high temperatures, as an insulating layer. With 2 wt % PSA as an insulating layer and annealed at 700 °C for 1 h, the FeSiAl SMPCs achieved the best magnetic properties, including the lowest core loss of 184 mW/cm3 (measured at 0.1 T and 50 kHz) and highest permeability of 96.

The effect of the insulating layer thickness on the piezoresistive properties of polysilicon film

Vacuum ◽  
1991 ◽  
Vol 42 (16) ◽  
pp. 1079
Author(s):  
Zhou Weiping ◽  
Weng Juewei ◽  
Lai Zongsheng ◽  
Tan Songshen
Keyword(s):  
Layer Thickness ◽  
Insulating Layer ◽  
Polysilicon Film

Numerical Calculation of Insulating Layer Thickness of Rural Water Supply Pipe in Permafrost Regions

2013 ◽  
Vol 864-867 ◽  
pp. 2022-2026 ◽  
Author(s):  
Li Bai ◽  
Yan Wang
Keyword(s):  
Water Supply ◽  
Layer Thickness ◽  
Reliable Operation ◽  
Buried Pipe ◽  
Insulating Layer ◽  
Rural Water Supply ◽  
Regular Production ◽  
Supply Pipe ◽  
Rural Water ◽  
Permafrost Regions

In permafrost regions of China, the rural water treatment devices have problem in safe and reliable operation, especially in winter. The phenomenon of rural water supply pipes frost heave often happens and does great harm to water supply system’s reliable operation .Thus, the research of anti-freezing technologies are necessary for regular production and lives of peasants .In order to solve the problem, this article introduce the anti-freezing technology of straight-buried pipe with insulating layer. Through theoretical analysis and calculation, the insulating layer thickness can be determined.

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