Microwave Dielectric Characteristics of Glass-Added (1-x)Al2O3–xTiO2Ceramics

Tzou, Wen-Cheng; Chen, Ying–Chung; Chang, Sang-Li; Yang, Cheng‐Fu

doi:10.1143/jjap.41.7422

Cited by 14 publications

(5 citation statements)

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“…The Q × f value of nano α‐Al 2 O 3 ceramics with 0.5 wt% nano TiO 2 is higher than that without addition 8 . In order to lower the sintering temperature and achieve a zero τ f value for alumina ceramics, Tzou et al 13 added MgO–CaO–Al 2 O 3 –SiO 2 (MCAS) glass additions as a sintering aid to alumina ceramics. MCAS glass additions lowered the sintering temperature, but also led to a considerable decrease in the Q × f value 13 .…”

Section: Resultsmentioning

confidence: 99%

“…In order to lower the sintering temperature and achieve a zero τ f value for alumina ceramics, Tzou et al 13 added MgO–CaO–Al 2 O 3 –SiO 2 (MCAS) glass additions as a sintering aid to alumina ceramics. MCAS glass additions lowered the sintering temperature, but also led to a considerable decrease in the Q × f value 13 . Moreover, Miyauchi et al 10 utilized an annealing method to adjust the τ f value of 0.9Al 2 O 3 –0.1TiO 2 .…”

Section: Resultsmentioning

confidence: 99%

“…As most of the dielectric ceramics with high dielectric constants have positive τ f values, it is thereby desirable to search for materials having a high dielectric constant, high Q , and negative τ f in order to achieve this goal. Therefore, TiO 2 (ɛ r =100, Q × f ∼50 000 GHz, τ f =450 ppm/°C) 11 has often been utilized in controlling microwave dielectric properties and the sintering behavior 12,13 …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Microwave Dielectric Properties of Sintered Alumina Using Nano‐Scaled Powders of α Alumina and TiO₂

Huang¹,

Wang²,

Huang³

2007

Journal of the American Ceramic Society

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The microstructure and the microwave dielectric properties of nano‐scaled α alumina (α‐Al2O3) ceramics with various added amounts of nano‐scaled TiO2 have been investigated. The sintering temperature of nano‐scaled α alumina can be effectively lowered by increasing the TiO2 content. The Q×f values of nano‐scaled α alumina could be tremendously boosted by adding an appropriate amount of TiO2. However, introducing excessive TiO2 into the alumina ceramics would instead lead to a decrease in the Q×f values. The phases of TiO2 and Al2TiO5 co‐existed at 1350°C, and the maximum Q×f value appeared right after the eradication of TiO2 phase at 1400°C. Consequently, increasing the TiO2 content to 0.5 wt% yielded a Q×f value of 680 000 GHz (measured at 14 GHz) for nano‐scaled α alumina prepared at 1400°C for duration of 4 h. In addition, a very low loss tangent (tan δ) of 2 × 10−5 was also obtained at 14 GHz. The τf value is strongly correlated to the compositions and can be controlled through the existing phases. In fact, τf could be adjusted to near zero by adding 8 wt% TiO2 to α alumina ceramics. A dielectric constant (ɛr) of 10.81, a high Q×f value of 338 000 GHz (measured at 14 GHz), and a temperature coefficient of resonant frequency (τf) of 1.3 ppm/°C were obtained for nano‐scaled α alumina with 8 wt% TiO2 sintered at 1350°C for 4 h. Sintered ceramic samples were also characterized by X‐ray diffraction and scanning electron microscopy.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Microwave Dielectric Properties of Sintered Alumina Using Nano‐Scaled Powders of α Alumina and TiO₂

Huang¹,

Wang²,

Huang³

2007

Journal of the American Ceramic Society

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“…Since most of the dielectric ceramics with high-relative-permittivity have positive f values, it is thereby desirable to search for materials having high-relative-permittivity, high Q and negative f in order to achieve this goal. Therefore, TiO 2 has often been utilized in controlling microwave dielectric properties and the sintering behavior [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Phase evolution and microwave dielectric properties of TiO2-modified (Mg0.95Co0.05)2TiO4 ceramics

Huang

Chen

2011

Journal of Alloys and Compounds

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“…It has been known that microwave dielectric loss includes intrinsic loss mainly caused by the lattice vibration modes and the extrinsic loss predominated by crystallizability, second phases, oxygen vacancies, grain sizes, and densification, etc. [11][12][13] Clearly, density and grain crystallizability play an important role in controlling dielectric loss. In addition, it can be observed from Fig.…”

mentioning

confidence: 99%

Calcining Temperature Dependence of Microwave Dielectric Properties of (1-x)ZnAl₂O₄–xTiO₂ (x=0.21) Ceramics

Lei

Zhu

et al. 2007

jjap

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(1-x)ZnAl2O4–xTiO2 (x = 0.21) ceramics were synthesized at 1500 °C using the solid-state reaction after the starting powders were calcined at 1050–1250 °C. The effects of calcining temperature on the microstructures, phase compositions, and microwave dielectric properties of the ceramics had been investigated. In the calcined (1-x)ZnAl2O4–xTiO2 (x = 0.21) powders, the amount of the secondary phase Zn2Ti3O8 decreases gradually with increasing calcining temperature and it disappears at more than 1150 °C. The εr and Q·f values increase slowly with increasing calcining temperature and then decrease after reaching the maximum value at 1150 °C, whereas the τf values are nearly independent of the calcining temperature and approach zero. When the calcining temperature reaches 1150 °C, the optimal microwave dielectric properties of the (1-x)ZnAl2O4–xTiO2 (x = 0.21) ceramics can be exhibited with a εr of 11.6, a Q·f of 74,000 GHz (at about 6.5 GHz), and a τf of -0.4 ppm/°C.

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Microwave Dielectric Characteristics of Glass-Added (1-x)Al₂O₃–xTiO₂Ceramics

Cited by 14 publications

References 4 publications

Microwave Dielectric Properties of Sintered Alumina Using Nano‐Scaled Powders of α Alumina and TiO₂

Microwave Dielectric Properties of Sintered Alumina Using Nano‐Scaled Powders of α Alumina and TiO₂

Phase evolution and microwave dielectric properties of TiO2-modified (Mg0.95Co0.05)2TiO4 ceramics

Calcining Temperature Dependence of Microwave Dielectric Properties of (1-x)ZnAl₂O₄–xTiO₂ (x=0.21) Ceramics

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Microwave Dielectric Characteristics of Glass-Added (1-x)Al2O3–xTiO2Ceramics

Cited by 14 publications

References 4 publications

Microwave Dielectric Properties of Sintered Alumina Using Nano‐Scaled Powders of α Alumina and TiO2

Microwave Dielectric Properties of Sintered Alumina Using Nano‐Scaled Powders of α Alumina and TiO2

Phase evolution and microwave dielectric properties of TiO2-modified (Mg0.95Co0.05)2TiO4 ceramics

Calcining Temperature Dependence of Microwave Dielectric Properties of (1-x)ZnAl2O4–xTiO2 (x=0.21) Ceramics

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Product

Resources

About

Microwave Dielectric Characteristics of Glass-Added (1-x)Al₂O₃–xTiO₂Ceramics

Microwave Dielectric Properties of Sintered Alumina Using Nano‐Scaled Powders of α Alumina and TiO₂

Microwave Dielectric Properties of Sintered Alumina Using Nano‐Scaled Powders of α Alumina and TiO₂

Calcining Temperature Dependence of Microwave Dielectric Properties of (1-x)ZnAl₂O₄–xTiO₂ (x=0.21) Ceramics