Influence of thermal treatments on the low frequency conductivity and microwave dielectric loss of CaTiO3 ceramics

In the present work, the microstructure and microwave dielectric properties of BaTi4O9 ceramics derived from a sol-gel precursor were presented. Density measuring results demonstrated that the largest densities of ceramic sample about 96.7% could be reached by virtue of a cool iso-static press and a sintering process at at 1300 °C for 6 hours. The dielectric constant (εr), quality factor (Q×f) and the temperature coefficients (τf) of the BaTi4O9 ceramic samples were 36.65, 28000 GHz, +20.2 ppm/°C, respectively. XRD, SEM and XPS were used to characterize the microstructure of the ceramics samples. Substantial Ti3+ was proposed to be the cause of dielectric loss.

Download Full-text

Microstructures and microwave dielectric properties of Mg+1Ti O3+1 ceramics with ultralow dielectric loss

Materials Letters ◽

10.1016/j.matlet.2016.09.025 ◽

2016 ◽

Vol 185 ◽

pp. 432-435 ◽

Cited By ~ 4

Author(s):

Xianpei Huang ◽

Fei Liu ◽

Changlai Yuan ◽

Xinyu Liu ◽

Jingjing Qu ◽

...

Keyword(s):

Dielectric Properties ◽

Dielectric Loss ◽

Microwave Dielectric Properties ◽

Microwave Dielectric

Download Full-text

Correlation between the 1:2 atomic order and microwave dielectric loss in the off-stoichiometric Ba(Zn1/3Ta2/3)O3

Journal of the European Ceramic Society ◽

10.1016/j.jeurceramsoc.2018.03.036 ◽

2018 ◽

Vol 38 (9) ◽

pp. 3412-3415 ◽

Cited By ~ 9

Author(s):

Jintara Padchasri ◽

Rattikorn Yimnirun ◽

Taras Kolodiazhnyi

Keyword(s):

Dielectric Loss ◽

Atomic Order ◽

Microwave Dielectric

Download Full-text

Far infrared dielectric loss and low frequency Raman scattering in chalcogenide glasses

1987 Twelth International Conference on Infrared and Millimeter Waves ◽

10.1109/irmm.1987.9126971 ◽

1987 ◽

Author(s):

U. Strom ◽

J. C. Culbertson ◽

J. A. Freitas

Keyword(s):

Dielectric Loss ◽

Raman Scattering ◽

Chalcogenide Glasses ◽

Low Frequency ◽

Far Infrared

Download Full-text

Microwave Dielectric Loss Characterization of Silicon Carbide Wafers

Materials Science Forum ◽

10.4028/www.scientific.net/msf.527-529.733 ◽

2006 ◽

Vol 527-529 ◽

pp. 733-736

Author(s):

Timothy Bogart ◽

W.J. Everson ◽

Rick D. Gamble ◽

Ed Oslosky ◽

David Snyder ◽

...

Keyword(s):

Silicon Carbide ◽

Dielectric Loss ◽

Microwave Cavity ◽

High Yield ◽

Microwave Dielectric ◽

Mapping System ◽

High Frequency Devices ◽

Nondestructive Characterization ◽

Initial Results

Semi-insulating silicon carbide (SiC) wafers are important as substrates for high frequency devices such as AlGaN-GaN HEMT’s. A nondestructive characterization technique has been developed to measure the dielectric properties of SiC wafers in the GHz frequency range where the devices will operate in order to validate wafers for high yield working devices. The dielectric loss is measured at approximately 16 GHz in a split microwave cavity. Initial results show a correlation where the dielectric loss decreases as the resistivity increases, where the resistivity was measured using a Contactless Resistivity Mapping system (COREMA). The uniformity of dielectric loss across SiC wafers was evaluated using a split post dielectric resonator cavity fixed at 5.5GHz to measure the dielectric loss at five points on a wafer. Dielectric loss as a function of temperature from room temperature to 400°C was also studied.

Download Full-text

Dielectric Property of Laminated AlN/BN Ceramic Composites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.620-622.359 ◽

2009 ◽

Vol 620-622 ◽

pp. 359-362

Author(s):

Tao Zhang ◽

Hai Yun Jin ◽

Rui Zhou ◽

Ji Feng Zhao ◽

Zhi Hao Jin

Keyword(s):

Dielectric Property ◽

Dielectric Loss ◽

Low Frequency ◽

Ceramic Composites ◽

Space Charge Polarization ◽

Frequency Range ◽

Pressing Temperature ◽

Polarization Mechanism ◽

The Relationship ◽

Dielectric Loss Increase

The relationship between the processing technology and the dielectric property of the laminated AlN/h-BN ceramic composites has been studied. The results showed that the main polarization mechanism of laminated ceramic composites in low frequency range is space charge polarization at the interface of AlN layer and BN layer. Due to the affection of porosity, the permittivity increases and the dielectric loss decreases with increasing the hot pressing temperature. The permittivity increases and the dielectric loss decreases with increasing thickness ratio of different layer., Both permittivity and dielectric loss increase with increasing the content of AlN doping in BN layer.

Download Full-text