The dielectric ceramics in the system Ca2+xLa8−x(SiO4)6−x(PO4)xO2 (x= 0, 2, 4 and 6) were investi... more The dielectric ceramics in the system Ca2+xLa8−x(SiO4)6−x(PO4)xO2 (x= 0, 2, 4 and 6) were investigated as promising materials for microwave applications. The ceramics were prepared by the conventional solid state ceramic route. The relative permittivity of ceramics was in the range 11.7-14.4 and all the compositions showed low dielectric loss (tan δ < 10 -3 ) at 1 MHz. The composition with x=2 showed good microwave dielectric properties of εr=13.8, Quxf = 27900 GHz and τf = -11 ppm/ o C.
Butyl rubber-SrTiO3 flexible composites were prepared through sigma mixing followed by hot pressi... more Butyl rubber-SrTiO3 flexible composites were prepared through sigma mixing followed by hot pressing. The dielectric properties were studied at different frequencies. Theoretical models were used to predict the effective relative permittivity of the composites and the results were correlated with the experimental data. The relative permittivity of the composite was observed to increase with the volume fraction of the filler,
ABSTRACT The present paper reports the preparation and characterization of Polystyrene-Silver com... more ABSTRACT The present paper reports the preparation and characterization of Polystyrene-Silver composites for embedded capacitor applications. The composites have been prepared by ultrasonic mixing followed by hot pressing. The percolation threshold is found to be decreasing from 0.1 Vf for silver of particle size
The LiMgPO4 ceramic has been prepared through the solid state ceramic route. The powder has an av... more The LiMgPO4 ceramic has been prepared through the solid state ceramic route. The powder has an average particle size of 1.1 m and BET surface area of 2.7 m2 g−1. Good dispersion of LiMgPO4 has been achieved in ethanol/xylene mixture with the addition of 2 wt.% fish oil. The tape casting slurry of LiMgPO4 with typical pseudoplastic behavior has been prepared and cast into thin tapes of thickness 70 m. LiMgPO4 green tape shows a tensile strength of 0.22 MPa and average surface roughness of 0.25 m. The green tape has an εr of 3.2 and tan δ of 0.0688 at 5 GHz. The thermo-laminated tape (4 layers) sintered at 950 ◦C/2 h shows good microwave dielectric properties: εr = 6.4 and tan δ = 0.0002. LiMgPO4 has a coefficient of thermal expansion of 10.5 ppm/◦C and thermal conductivity of 7.1 W m−1 K−1.
ABSTRACT The 10 mol% ZnO–2 mol% B 2 O 3 –8 mol% P 2 O 5 –80 mol% TeO 2 (ZBPT) glass was prepared ... more ABSTRACT The 10 mol% ZnO–2 mol% B 2 O 3 –8 mol% P 2 O 5 –80 mol% TeO 2 (ZBPT) glass was prepared by quenching as well as slowly cooling the melt. The ZBPT glass prepared by both methods show similar microwave dielectric properties. ZBPT glass has an e r of 22.5 (at 7 GHz), Q u 3 f of 1500 GHz, and τ f of À100 ppm/°C. The ceramic-glass composites of Sr 2 ZnTeO 6 (SZT) and ZBPT is prepared through two conve-nient methods: (a) conventional way of co-firing the ceramic with ZBPT glass powder and (b) a nonconventional facile route by co-firing the ceramic with precursor oxide mixture of ZBPT glass at 950°C. In the former route, SZT + 5 wt% ZBPT com-posite sintered at 950°C showed moderately good microwave dielectric properties (e r = 13.4, Q u 3 f = 4500 GHz and τ f = À52 ppm/°C). Although the SZT + 5 wt% ZBPT compos-ite prepared through the nonconventional method also showed simi-lar microwave dielectric properties (e r = 13.8, Q u 3 f = 5300 GHz and τ f = À50 ppm/°C), the synthesis procedure is much simplified in the latter case. The composites are found to be chemi-cally compatible with Ag. The composite containing 5 wt% ZBPT prepared through conventional and nonconventional ways shows linear coefficients of thermal expansion of 7.0 ppm/°C and 7.1 ppm/°C, respectively. Both the composites have a room-tem-perature thermal conductivity of 2.1 Wm À1 K À1 .
The dielectric ceramics in the system Ca2+xLa8−x(SiO4)6−x(PO4)xO2 (x= 0, 2, 4 and 6) were investi... more The dielectric ceramics in the system Ca2+xLa8−x(SiO4)6−x(PO4)xO2 (x= 0, 2, 4 and 6) were investigated as promising materials for microwave applications. The ceramics were prepared by the conventional solid state ceramic route. The relative permittivity of ceramics was in the range 11.7-14.4 and all the compositions showed low dielectric loss (tan δ < 10 -3 ) at 1 MHz. The composition with x=2 showed good microwave dielectric properties of εr=13.8, Quxf = 27900 GHz and τf = -11 ppm/ o C.
Butyl rubber — Ca4La6(SiO4)4(PO4)2O2 — composites have been prepared by sigma mixing and
hot pre... more Butyl rubber — Ca4La6(SiO4)4(PO4)2O2 — 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
The dielectric ceramics in the system Ca2+xLa8−x(SiO4)6−x(PO4)xO2 (x= 0, 2, 4 and 6) were investi... more The dielectric ceramics in the system Ca2+xLa8−x(SiO4)6−x(PO4)xO2 (x= 0, 2, 4 and 6) were investigated as promising materials for microwave applications. The ceramics were prepared by the conventional solid state ceramic route. The relative permittivity of ceramics was in the range 11.7-14.4 and all the compositions showed low dielectric loss (tan δ < 10 -3 ) at 1 MHz. The composition with x=2 showed good microwave dielectric properties of εr=13.8, Quxf = 27900 GHz and τf = -11 ppm/ o C.
Butyl rubber-SrTiO3 flexible composites were prepared through sigma mixing followed by hot pressi... more Butyl rubber-SrTiO3 flexible composites were prepared through sigma mixing followed by hot pressing. The dielectric properties were studied at different frequencies. Theoretical models were used to predict the effective relative permittivity of the composites and the results were correlated with the experimental data. The relative permittivity of the composite was observed to increase with the volume fraction of the filler,
ABSTRACT The present paper reports the preparation and characterization of Polystyrene-Silver com... more ABSTRACT The present paper reports the preparation and characterization of Polystyrene-Silver composites for embedded capacitor applications. The composites have been prepared by ultrasonic mixing followed by hot pressing. The percolation threshold is found to be decreasing from 0.1 Vf for silver of particle size
The LiMgPO4 ceramic has been prepared through the solid state ceramic route. The powder has an av... more The LiMgPO4 ceramic has been prepared through the solid state ceramic route. The powder has an average particle size of 1.1 m and BET surface area of 2.7 m2 g−1. Good dispersion of LiMgPO4 has been achieved in ethanol/xylene mixture with the addition of 2 wt.% fish oil. The tape casting slurry of LiMgPO4 with typical pseudoplastic behavior has been prepared and cast into thin tapes of thickness 70 m. LiMgPO4 green tape shows a tensile strength of 0.22 MPa and average surface roughness of 0.25 m. The green tape has an εr of 3.2 and tan δ of 0.0688 at 5 GHz. The thermo-laminated tape (4 layers) sintered at 950 ◦C/2 h shows good microwave dielectric properties: εr = 6.4 and tan δ = 0.0002. LiMgPO4 has a coefficient of thermal expansion of 10.5 ppm/◦C and thermal conductivity of 7.1 W m−1 K−1.
ABSTRACT The 10 mol% ZnO–2 mol% B 2 O 3 –8 mol% P 2 O 5 –80 mol% TeO 2 (ZBPT) glass was prepared ... more ABSTRACT The 10 mol% ZnO–2 mol% B 2 O 3 –8 mol% P 2 O 5 –80 mol% TeO 2 (ZBPT) glass was prepared by quenching as well as slowly cooling the melt. The ZBPT glass prepared by both methods show similar microwave dielectric properties. ZBPT glass has an e r of 22.5 (at 7 GHz), Q u 3 f of 1500 GHz, and τ f of À100 ppm/°C. The ceramic-glass composites of Sr 2 ZnTeO 6 (SZT) and ZBPT is prepared through two conve-nient methods: (a) conventional way of co-firing the ceramic with ZBPT glass powder and (b) a nonconventional facile route by co-firing the ceramic with precursor oxide mixture of ZBPT glass at 950°C. In the former route, SZT + 5 wt% ZBPT com-posite sintered at 950°C showed moderately good microwave dielectric properties (e r = 13.4, Q u 3 f = 4500 GHz and τ f = À52 ppm/°C). Although the SZT + 5 wt% ZBPT compos-ite prepared through the nonconventional method also showed simi-lar microwave dielectric properties (e r = 13.8, Q u 3 f = 5300 GHz and τ f = À50 ppm/°C), the synthesis procedure is much simplified in the latter case. The composites are found to be chemi-cally compatible with Ag. The composite containing 5 wt% ZBPT prepared through conventional and nonconventional ways shows linear coefficients of thermal expansion of 7.0 ppm/°C and 7.1 ppm/°C, respectively. Both the composites have a room-tem-perature thermal conductivity of 2.1 Wm À1 K À1 .
The dielectric ceramics in the system Ca2+xLa8−x(SiO4)6−x(PO4)xO2 (x= 0, 2, 4 and 6) were investi... more The dielectric ceramics in the system Ca2+xLa8−x(SiO4)6−x(PO4)xO2 (x= 0, 2, 4 and 6) were investigated as promising materials for microwave applications. The ceramics were prepared by the conventional solid state ceramic route. The relative permittivity of ceramics was in the range 11.7-14.4 and all the compositions showed low dielectric loss (tan δ < 10 -3 ) at 1 MHz. The composition with x=2 showed good microwave dielectric properties of εr=13.8, Quxf = 27900 GHz and τf = -11 ppm/ o C.
Butyl rubber — Ca4La6(SiO4)4(PO4)2O2 — composites have been prepared by sigma mixing and
hot pre... more Butyl rubber — Ca4La6(SiO4)4(PO4)2O2 — 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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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
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