Microwave Dielectric Characteristics of Butyl Rubber- Barium Titanate Composites

Butyl rubber-micron barium titanate (BR/BT) and butyl rubber-nano barium titanate (BR/nBT) composites were prepared by sigma mixing followed by hot pressing. The tensile tests show that both the composites were mechanically flexible. The microwave dielectric properties of both BR/BT and BR/nBT composites were investigated as a function of ceramic loading and were found to be improved with filler content. The butyl rubber has relative permittivity (εr) of 2.4 and loss tangent (tan δ) of 0.0017 at 5 GHz. At a filler loading of 0.24 volume fraction (vf) of micron sized barium titanate (BaTiO3) powder loading, the composite attained a εr of 7 and tan δ of 0.014 and for the same filler content of nano BaTiO3 the composite have εr of 8.9 and tan δ of 0.019 at 5 GHz. The thermal stability of the relative permittivity of both the composites was investigated. The experimental values of εr of both BR/BT and BR/nBT composites were compared with theoretical models.

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HDPE Matrix Composites Filled With Ca4La6(SiO4)4(PO4)2O2 for Microwave Substrate Applications

Journal of Electronic Packaging ◽

10.1115/1.4027089 ◽

2014 ◽

Vol 136 (3) ◽

Cited By ~ 5

Author(s):

Dhanesh Thomas ◽

Mailadil T. Sebastian

Keyword(s):

Dielectric Loss ◽

Relative Permittivity ◽

Volume Fraction ◽

Linear Thermal Expansion ◽

Theoretical Models ◽

Ceramic Composites ◽

Filler Loading ◽

Scanning Electron Micrographs ◽

Melt Mixing ◽

5 Ghz

Polymer–ceramic composites have been prepared by dispersing Ca4La6(SiO4)4(PO4)2O2 (CLSP) ceramic filler in high density polyethylene (HDPE) matrix through melt mixing. Scanning electron micrographs reveal the extent of filler dispersion. The dielectric properties at 1 MHz and 5 GHz have been investigated as a function of filler content. The relative permittivity increases with filler loading, maintaining a low dielectric loss. The composite with highest filler loading of 0.4 volume fraction shows a relative permittivity of 5.1 and dielectric loss of 2.3 × 10−3 at 5 GHz. Experimentally observed values of relative permittivity at 5 GHz have been compared with the values calculated using various theoretical models. Both the coefficient of linear thermal expansion and tensile strength have been observed to decrease with filler loading, reaching a minimum value of 117 ppm/ °C and 20.7 MPa, respectively, at 0.4 volume fraction of filler. The composite with maximum filler loading of 0.4 volume fraction shows the highest thermal conductivity (TC) and is 1.2 W m−1 K−1.

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Investigation of Surface Scaling, Optical and Microwave Dielectric Studies of Bi0.5Na0.5TiO3 thin Films

10.21203/rs.3.rs-332237/v1 ◽

2021 ◽

Author(s):

Srinivas Pattipaka ◽

Pamu D ◽

Pundareekam Goud J ◽

James Raju K C ◽

Gbinda Pradhan ◽

...

Keyword(s):

Thin Films ◽

Dielectric Properties ◽

Microwave Dielectric Properties ◽

Secondary Phase ◽

Close Relation ◽

Degree Of Crystallinity ◽

Microwave Dielectric ◽

Potential Applications ◽

Tan Δ ◽

5 Ghz

Abstract Herein, we have investigated the optical and microwave dielectric properties of Bi 0.5 Na 0.5 TiO 3 (BNT) thin films grown under different oxygen pressure ( P O2 ) using pulsed laser deposition (PLD) technique. The X-ray diffraction measurements confirms the single phase of BNT along with secondary phase and further reduction in secondary phase and increase in BNT phase with P O2 , signifies the close relation between the crystal structure and oxygen content. The shift of Raman-active TO1, TO2 and TO3 modes towards higher wavelengths and increase in mode intensity with P O2 indicating the films degree of crystallinity. The local roughness ( α loc ) of all films obtained as ~ 0.85, and the interface width ( w ) and lateral correlation length ( ξ ) of films varies with P O2 . Also, the films exhibit the increase in refractive index and reduction in optical bandgap of due to improvement in crystallinity and reduction in the oxygen vacancies. The microwave dielectric properties show a strong P O2 depends with higher dielectric constant ( ε r = 336) with lower loss (tan δ = 0.0093) at 5 GHz which show the potential applications in high frequency devices.

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PREPARATION AND CHARACTERIZATION OF MECHANICALLY FLEXIBLE RUBBER-CERAMIC COMPOSITE DIELECTRICS

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194513010039 ◽

2013 ◽

Vol 22 ◽

pp. 148-152

Author(s):

DHANESH THOMAS ◽

M. T. SEBASTIAN

Keyword(s):

Dielectric Loss ◽

Hot Pressing ◽

Relative Permittivity ◽

Ceramic Composite ◽

Temperature Stability ◽

Theoretical Models ◽

Butyl Rubber ◽

Low Dielectric

Butyl rubber — Ca 4 La 6( SiO 4)4( PO 4)2 O 2 — composites have been prepared by sigma mixing and hot pressing. The relative permittivity of the composites varies from 3 to 5.3 at 1 MHz. All the composites show low dielectric loss of the order of 10−3 at 1 MHz. The experimentally observed values of relative permittivity are correlated with those calculated using various theoretical models. The composites show good temperature stability of relative permittivity.

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Microwave Dielectric Properties of Gallium-Doped Hexagonal Barium Titanate Ceramics

Journal of the American Ceramic Society ◽

10.1111/j.1151-2916.2003.tb03330.x ◽

2003 ◽

Vol 86 (3) ◽

pp. 511-513 ◽

Cited By ~ 40

Author(s):

Antonio Feteira ◽

Kumaravinothan Sarma ◽

Neil McN. Alford ◽

Ian M. Reaney ◽

Derek C. Sinclair

Keyword(s):

Dielectric Properties ◽

Barium Titanate ◽

Microwave Dielectric Properties ◽

Microwave Dielectric ◽

Titanate Ceramics

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Effect of Sintering Temperature on CuO Doped Barium Zinc Tantalate (BZT) Dielectric Properties

Materials Science Forum ◽

10.4028/www.scientific.net/msf.840.8 ◽

2016 ◽

Vol 840 ◽

pp. 8-13

Author(s):

Hidayani Jaafar ◽

Zainal Arifin Ahmad ◽

Mohd Fadzil Ain

Keyword(s):

Dielectric Constant ◽

Dielectric Properties ◽

Relative Density ◽

Sintering Temperature ◽

Microwave Dielectric Properties ◽

Solid State Method ◽

Microwave Dielectric ◽

Constant E ◽

State Method ◽

Tan Δ

The structure and dielectric properties of Barium Zinc Tantalate (BZT) doped by copper oxide (CuO) with a variety of values of mol% doping from 0, 0.1, 0.25, 1.0, 1.5 and 2.5 were prepared using a solid state method. The addition of CuO did not disturb the 1:2 ordering structure of the BZT ceramic. The grain size increased when the addition of doping increased. A small amount of doping elements increased the relative density. The dielectric constant (ɛr) value of the BZT significantly improved with the addition of the CuO for the specimens sintered at 1250°C and it could be explained by the increase of the relative density. The tan δ of the CuO doped with BZT ceramics is lower than pure BZT ceramics, and decreases as the CuO content increases. Meanwhile, for the percentage of bandwidth (%BW) it is shown that the best result is produced when it is doped with 0.25 mol% CuO and sintered at 1250°C. The best microwave dielectric properties obtained were ɛr=70.28, tan δ = 0.024, %BW = 7.83 which occurred for the 0.25 mol% doped CuO and when sintered at 1250°C/4 h.

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SYNTHESIS AND MICROWAVE DIELECTRIC PROPERTIES OF Li2MgSiO4 CERAMICS PREPARED USING CITRATE GEL ROUTE

Journal of Advanced Dielectrics ◽

10.1142/s2010135x11000203 ◽

2011 ◽

Vol 01 (02) ◽

pp. 209-213 ◽

Cited By ~ 4

Author(s):

S. GEORGE ◽

V. K. SAJITH ◽

M. T. SEBASTIAN ◽

S. RAMAN ◽

P. MOHANAN

Keyword(s):

Dielectric Properties ◽

Solid State ◽

Sintering Temperature ◽

Microwave Dielectric Properties ◽

Low Temperature Sintering ◽

Microwave Dielectric ◽

Ceramic Route ◽

Low Sintering Temperature ◽

Tan Δ ◽

Zinc Borosilicate

The comparison of the low temperature sintering and the microwave dielectric properties of Li2MgSiO4 (LMS) ceramics prepared by citrate gel (CG) route and solid state (SS) ceramic route are discussed in this paper. The LMS prepared using CG route sintered at 1175°C/2 h has εr = 5.3 and tan δ = 1 × 10−3 at 9 GHz. The sintering temperature of LMS is lowered to 950°C with the addition of 5 wt% lithium magnesium zinc borosilicate glass and has εr = 5.6 and tan δ = 2 × 10-3 at 9 GHz. The amount of glass required to lower the sintering temperature of ceramics prepared using CG are slightly higher than that of SS ceramic route. The LMS ceramics prepared using SS ceramic route shows excellent microwave dielectric properties with low sintering temperature compared to CG route.

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Preparation, microstructure and microwave dielectric properties of sprayed PFA/barium titanate composite films

Composites Science and Technology ◽

10.1016/j.compscitech.2016.04.021 ◽

2016 ◽

Vol 129 ◽

pp. 198-204 ◽

Cited By ~ 8

Author(s):

Qin Lei ◽

Claire E.J. Dancer ◽

Chris R.M. Grovenor ◽

Patrick S. Grant

Keyword(s):

Dielectric Properties ◽

Barium Titanate ◽

Composite Films ◽

Microwave Dielectric Properties ◽

Microwave Dielectric

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A low-firing melilite ceramic Ba2CuGe2O7 and compositional modulation on microwave dielectric properties through Mg substitution

Journal of Advanced Ceramics ◽

10.1007/s40145-020-0424-3 ◽

2020 ◽

Author(s):

Changzhi Yin ◽

Zezong Yu ◽

Longlong Shu ◽

Laijun Liu ◽

Yan Chen ◽

...

Keyword(s):

Crystal Structure ◽

Dielectric Properties ◽

Resonance Frequency ◽

Temperature Coefficient ◽

Quality Factor ◽

Relative Permittivity ◽

Microwave Dielectric Properties ◽

Sintering Behavior ◽

Magnesium Doping ◽

Microwave Dielectric

AbstractA melilite Ba2CuGe2O7 ceramic was characterized by low sintering temperature and moderate microwave dielectric properties. Sintered at 960 °C, the Ba2CuGe2O7 ceramic had a high relative density 97%, a low relative permittivity (εr) 9.43, a quality factor (Q×f) of 20,000 GHz, and a temperature coefficient of resonance frequency (τf) −76 ppm/°C. To get a deep understanding of the relationship between composition, structure, and dielectric performances, magnesium substitution for copper in Ba2CuGe2O7 was conducted. Influences of magnesium doping on the sintering behavior, crystal structure, and microwave dielectric properties were studied. Mg doping in Ba2CuGe2O7 caused negligible changes in the macroscopic crystal structure, grain morphology, and size distribution, while induced visible variation in the local structure as revealed by Raman analysis. Microwave dielectric properties exhibit a remarkable dependence on composition. On increasing the magnesium content, the relative permittivity featured a continuous decrease, while both the quality factor and the temperature coefficient of resonance frequency increased monotonously. Such variations in dielectric performances were clarified in terms of the polarizability, packing fraction, and band valence theory.

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