scholarly journals Synthesis and Study of Structural and Dielectric Properties of Dy-Ho Doped Mn-Zn Ferrite Nanoparticles

2021 ◽  
Author(s):  
Krishtappa Manjunatha ◽  
Veerabhadrappa Jagadeesha Angadi ◽  
Brian Jeevan Fernandes ◽  
Keralapura Parthasarathy Ramesh
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Ac Conductivity ◽  
Ferrite Nanoparticles ◽  
The Real ◽  
Low Dielectric ◽  
Zn Ferrite ◽  
Xrd Patterns ◽  
The One

The Dy-Ho doped Mn-Zn Ferrite nanoparticles have been synthesized by solution combustion method using mixture of fuels as glucose and urea. The synthesized samples of structural properties were characterized through XRD (X-ray diffraction) and dielectric properties were studied through impedance analyzer. The XRD patterns of all samples confirms the spinel cubic structure having space group Fd3m. Further all synthesized samples reveal the single-phase formation without any secondary phase. The lattice parameters and hopping lengths were increases with increase of Dy-Ho concentration. SEM micrographs shows the porous nature for all samples. The crystallite size increases with increase of Dy-Ho concentration. The Dielectric properties of all the samples were explained by using Koop’s phenomenological theory. The real part of dielectric constant, imaginary part of dielectric constant and dielectric loss tangent were decreases with increase of frequency. Th AC conductivity increases with increase of frequency. The real part of impedance spectra decreases with increase of frequency for all samples. The Cole-Cole plots shows the one semicircle for all samples. The high ac conductivity and low dielectric loss observed for all samples at high frequency region and this samples are reasonable for power transformer applications at high frequencies.

Synthesis and Dielectric Properties of [(K0.5Na0.5)0.935Li0.065]NbO3 Added with Mn for Piezoelectric Ceramic

2016 ◽  
Vol 675-676 ◽  
pp. 635-638
Author(s):  
Jukkrit Kongphimai ◽  
Hassakorn Wattanasarn ◽  
Tosawat Seetawan
Keyword(s):  
Crystal Structure ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Physical Properties ◽  
Crystallite Size ◽  
Piezoelectric Ceramic ◽  
Theoretical Density ◽  
Milling Method ◽  
Xrd Patterns

[(K0.5Na0.5 )0.935Li0.065]NbO3–Mn ceramics (Mn = 0, 1.50 and 3 mol %) (KNNL–Mn) were synthesized and measured dielectric properties. Which the K2CO3, Na2CO3, Li2CO3, Nb2O5 and MnO2 (0, 1.5, 3 mol%) were mixed by ball milling method and calcined powders at 1,073 K for 4 h and the sintered at 1,343 K for 2 h in air. The crystal structure was analyzed by XRD technique, the crystallite size was identified by Scherrer’s equation and calculated the theoretical density. It was found that, the XRD patterns of the KNNL–Mn ceramics added with Mn contents was indicated the tetragonal structure and. the crystallite size of Mn = 0, 1.50 and 3 mol% about 32 nm, 34 nm and 57 nm, respectively. The physical properties of the KNNL–Mn ceramics was found that the maximum theoretical density of 90.79 % for Mn = 1.50 mol%. The dielectric constant was found to be maximum of 909.77 and dielectric loss of 0.48 for Mn = 3 mol%.

Photosensitive Polyimide having low loss tangent for RF application

2018 ◽  
Vol 2018 (1) ◽  
pp. 000476-000482 ◽  
Author(s):  
Masao Tomikawa ◽  
Hitoshi Araki ◽  
Yohei Kiuchi ◽  
Akira Shimada
Keyword(s):  
Molecular Structure ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
High Frequency ◽  
Low Dielectric Constant ◽  
Low Loss ◽  
Elongation At Break ◽  
Low Dielectric ◽  
The Poor

Abstract Progress of 5G telecommunication and mm radar for autopilot, high frequency operation is required. Insulator materials having low loss at high frequency is desired for the applications. We designed the low dielectric constant, and low dielectric loss materials examined molecular structure of the polyimide and found that permittivity 2.6 at 20GHz, dielectric loss 0.002. Furthermore, in consideration of mechanical properties such as the toughness and adhesion to copper from a point of practical use. Dielectric properties largely turned worse when giving photosensitivity. To overcome the poor dielectric properties, we designed the photosensitive system. After all, we successfully obtained 3.5 of dielectric constant and 0.004 of dielectric loss, and 100% of elongation at break. In addition, we offered a B stage sheet as well as varnish. These materials are applicable to re-distribution layer of FO-WLP, Interposer and other RF applications for microelectronics.

Dielectric Properties of Li-Doped CaCu3Ti4O12 Ceramics

2011 ◽  
Vol 687 ◽  
pp. 251-256 ◽  
Author(s):  
Ying He ◽  
Huai Wu Zhang ◽  
Yuan Xun Li ◽  
Wei Wei Ling ◽  
Yun Yan Wang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Secondary Phase ◽  
Doping Amount ◽  
Spectroscopy Analysis ◽  
Low Dielectric ◽  
Tan Δ ◽  
High Dielectric ◽  
Impedance Spectroscopy Analysis

CaCu3Ti4O12 ceramics doped with 0-2.0 wt% Li2CO3 were prepared by the solid-state reaction, and their electric and dielectric properties were investigated. It is found that these ceramics had the properties of high dielectric constant and comparatively low dielectric loss. At the doping amount of 0.5 wt%, the dielectric constant is kept to be 105 with weak frequency dependence below 105 Hz, and its loss tangent (tan δ) is suppressed below 0.1 between 300 Hz-5 kHz (with the minimum value of 0.06 at 1 kHz from 218 K to 338 K). The impedance spectroscopy analysis confirms that the decrease of dielectric loss is mainly due to the increase of resistance in the grain boundary, which may be related to the influence of Ti4O7 secondary phase. Our result indicates that doping Li2CO3 is an efficient method to optimize the dielectric properties of CaCu3Ti4O12.

scholarly journals Study of Dielectric Properties of Fenugreek Seeds (Trigonella Foenum Graecum)

2014 ◽  
Vol 66 (1) ◽  
pp. 17-28 ◽  
Author(s):  
Mohd. Shafi Khan ◽  
Vishal Singh Chandel ◽  
Rajiv Manohar ◽  
Jagdeesh Prasad Shukla
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Moisture Content ◽  
Ac Conductivity ◽  
Frequency Range ◽  
Fenugreek Seeds ◽  
Temperature Controller ◽  
Trigonella Foenum Graecum ◽  
Fenugreek Seed

Abstract The present paper studied the dielectric constant, dielectric loss, and ac conductivity of fenugreek seed, a medicinal seed (Trigonella foenum graecum), within the frequency range of 10 kHz and 10 MHz and the temperature range of 30°C and 50°C. Impedance gain/phase analyser (HP 4194 A) was used to measure the dielectric constant and the dielectric loss and Julabo (temperature controller, F-25, Germany) was used for keeping the temperature of fenugreek seeds constant. It was found that the dielectric constant and the dielectric loss decrease with the increase in the frequency while the same increase with the increase in temperature and moisture content. The ac conductivity increased with the increase in frequency, moisture and temperature.

Influence of MgO Content on Microstructure and Dielectric Properties in (BaSr)TiO3 Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 85-88
Author(s):  
Lin Hu ◽  
He Ping Zhou ◽  
Hao Xue ◽  
Chun Lai Xu
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Low Dielectric Constant ◽  
Microwave Technology ◽  
Phased Array Antennas ◽  
Strontium Titanium Oxide ◽  
Low Dielectric ◽  
Barium Strontium ◽  
High Dielectric

Barium strontium titanium oxide (BSTO) has great advantages and potentiality for the application of microwave technology. In order to be used in phased array antennas, high dielectric tunability, relatively low dielectric constant and low dielectric loss are required. In this paper, MgO was mixed into BSTO and the microstructure and dielectric properties of MgO-mixed BSTO bulk ceramics were investigated. The mole ratio of Ba and Sr was rather fixed to 5:5 in this study. It is observed that a small amount of MgO (5 wt%) has gone beyond the solubility limits of Mg in BSTO. The dielectric constant and dielectric loss of BSTO ceramics decreased with the increase of the content of MgO mixed. However, the tunability of MgO-mixed BSTO ceramics decreased at the same time. 20wt% MgO-mixed BSTO ceramics exhibits preferable dielectric properties with acceptable tunability.

Preparation and unique dielectric properties of nanoporous materials with well-controlled closed-nanopores

2016 ◽  
Vol 18 (28) ◽  
pp. 19183-19193 ◽  
Author(s):  
Cuijiao Zhao ◽  
Xiaonan Wei ◽  
Yawen Huang ◽  
Jiajun Ma ◽  
Ke Cao ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Porous Structure ◽  
Barrier Properties ◽  
Nanoporous Materials ◽  
Low Dielectric Constant ◽  
Low Dielectric ◽  
High Dielectric Loss ◽  
High Dielectric

Although general porous materials have a low dielectric constant, their uncontrollable opened porous structure results in high dielectric loss and poor barrier properties, thus limiting their application as interconnect dielectrics.

Sintering and Properties of CaO-Al2O3-B2O3-SiO2 System Glass Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 131-134
Author(s):  
Shao Hong Wang ◽  
He Ping Zhou ◽  
Ke Xin Chen ◽  
Xiao Shan Ning
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Glass Ceramics ◽  
Xrd Analysis ◽  
Low Dielectric Constant ◽  
Preparation Technology ◽  
Low Dielectric ◽  
Sintering Properties ◽  
Sintering Characteristics

Preparation technology and sintering characteristics of the CaO-Al2O3-B2O3-SiO2 system glass ceramics were investigated. Results showed that the glass ceramics of this system could be sintered at 850oC; the material has fine sintering properties, outstanding dielectric properties including low dielectric constant (about 4.85, 1GHz) and low dielectric loss (about 0.1%, 1GHz). XRD analysis indicated that the crystalline phases in the sintered body are mainly Al5(BO3)O6, a trace amount of SiO2 and CaSiO3.

An effective strategy for the preparation of intrinsic low-k and ultralow-loss dielectric polysiloxanes at high frequency by introducing trifluoromethyl groups into the polymers

2020 ◽  
Vol 11 (38) ◽  
pp. 6163-6170
Author(s):  
Fengping Liu ◽  
Xingrong Chen ◽  
Linxuan Fang ◽  
Jing Sun ◽  
Qiang Fang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
High Frequency ◽  
Low Dielectric Constant ◽  
Effective Strategy ◽  
Low Dielectric ◽  
5 Ghz ◽  
Low K ◽  
Trifluoromethyl Groups

Two new CF3-containing polysiloxanes with low dielectric constant (Dk) and dielectric loss (Df ) at a high frequency of 5 GHz were reported. The sample with two −CF3 groups exhibits better dielectric properties with Dk of 2.53 and ultralow Df of 1.66 × 10−3.

scholarly journals Surface-modified Zn0.5Ti0.5NbO4 particles filled polytetrafluoroethylene composite with extremely low dielectric loss and stable temperature dependence

2020 ◽  
Vol 9 (6) ◽  
pp. 726-738
Author(s):  
Hao Wang ◽  
Fuming Zhou ◽  
Jianming Guo ◽  
Yuanyuan Zhang ◽  
Hui Yang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Photoelectron Spectroscopy ◽  
Ceramic Composites ◽  
Surface Characteristic ◽  
Low Dielectric ◽  
Stable Temperature ◽  
Ptfe Composites ◽  
Microwave Substrate

AbstractPolymer-ceramic composites are widely applied in microwave substrate materials due to the excellent dielectric properties and simple preparation process recently. Polytetrafluoroethylene-based (PTFE) composites filled with Zn0.5Ti0.5NbO4 (ZTN) ceramic particles were fabricated by hot-pressing. The particles were modified by C14H19F13O3Si to enhance the interface compatibility between PTFE and ZTN powders, which was characterized by X-ray photoelectron spectroscopy (XPS) and contact angle. The surface characteristic of particles transformed into hydrophobicity and tight microstructure as well as better dielectric properties were obtained after the surface modification. The microstructure, dielectric, thermal, mechanical properties, and water absorption of the composites concerning ZTN content were investigated. Modified ZTN/PTFE composites with 50 vol% ZTN particles exhibit excellent dielectric properties with a high dielectric constant of 8.3, an extremely low dielectric loss of 0.00055 at 7 GHz, and a stable temperature coefficient of the dielectric constant of −12.2 ppm/°C. All the properties show modified ZTN particles filled PTFE composite is the potential material for microwave substrate application.

Dielectric Behaviour of Nanocrystalline Ni-Zn Ferrites Prepared by Oxalate Co-Precipitation Method

2013 ◽  
Vol 645 ◽  
pp. 56-59
Author(s):  
Shinde J. Tukaram ◽  
Gadkari B. Ashok ◽  
Vasambekar N. Pramod
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Ac Conductivity ◽  
Interfacial Polarization ◽  
Dielectric Behaviour ◽  
Precipitation Method ◽  
High Resistivity ◽  
Ceramic Method ◽  
Low Dielectric ◽  
Co Precipitation

Nickel–zinc ferrites with chemical formula Ni1-xZnxFe2O4 (x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) were prepared by oxalate co-precipitation method. The dielectric constant (ε') dielectric loss (tanδ) and AC conductivity (σac) of all the samples were determined at room temperature in the frequency range 20Hz -1MHz. The dielectric constant and dielectric loss are much smaller than those for samples prepared by ceramic method. The dielectric behaviour is attributed to the Maxwell–Wagner type interfacial polarization. AC conductivity of all the samples lies in the range 1.20×10-8 to 54.7×10-8 Ω-1cm-1. Low dielectric loss and high resistivity suggest the suitability of these ferrites for high frequency applications.

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