Doping Effects of Ta on Conductivity and Microwave Dielectric Loss of MgTiO3Ceramics

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.

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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

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

Materials Science and Engineering B ◽

10.1016/j.mseb.2010.12.010 ◽

2011 ◽

Vol 176 (5) ◽

pp. 401-405 ◽

Cited By ~ 12

Author(s):

Peng Hu ◽

Huan Jiao ◽

Chun-Hai Wang ◽

Xiao-Ming Wang ◽

Shi Ye ◽

...

Keyword(s):

Dielectric Loss ◽

Low Frequency ◽

Thermal Treatments ◽

Microwave Dielectric

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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

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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.

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Quantitative evaluation of spatial scale of carrier trapping at grain boundary by GHz-microwave dielectric loss spectroscopy

Journal of Physics Conference Series ◽

10.1088/1742-6596/924/1/012002 ◽

2017 ◽

Vol 924 ◽

pp. 012002 ◽

Cited By ~ 2

Author(s):

W. Choi ◽

Y. Tsutsui ◽

T. Miyakai ◽

T. Sakurai ◽

S. Seki

Keyword(s):

Dielectric Loss ◽

Grain Boundary ◽

Spatial Scale ◽

Quantitative Evaluation ◽

Carrier Trapping ◽

Microwave Dielectric

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The Dielectric Loss of Single Crystal and Polycrystalline TiO2

MRS Proceedings ◽

10.1557/proc-500-183 ◽

1997 ◽

Vol 500 ◽

Author(s):

Xiaoru Wang ◽

Alan Templeton ◽

Stuart J. Penn ◽

Neil McN. Alford

Keyword(s):

Dielectric Loss ◽

Single Crystal ◽

Mixed Valence ◽

Dielectric Materials ◽

Oxygen Stoichiometry ◽

Ion Conductor ◽

Microwave Dielectric ◽

Valence States ◽

Oxygen Ion Conductor

ABSTRACTThe dielectric loss of single crystal and polycrystalline TiO2 has been studied. In polycrystalline TiO2 the dielectric loss is determined by both the microstructure and by the oxygen stoichiometry. Experiments have been carried out to determine the influence of both the microstructure (particularly porosity) and the oxygen stoichiometry. The TiO2 powder has been doped with partially stabilised zirconia, an oxygen ion conductor, in order to modify the oxygen stoichiometry. Sintered discs have been examined for loss as a function zirconia doping, pore volume and as a function of temperature. The behaviour of the doped and undoped titania powders is significantly different. Since many microwave dielectric materials contain Ti eg Ba-Ti-O, Ba-Nd-Ti-O, (Ba-RE-Ti-O, RE=Rare Earth), Zr-Sn-Ti-O etc it is essential to understand the role of the titanium, particularly as it can exist in mixed valence states, and the role of oxygen and its influence on the dielectric loss.

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Effect of Thermal Stress on the Microwave Dielectric Properties of (300-X) nm MgTiO3 /(X) nm CaTiO3 Thin Films

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.45.2332 ◽

2006 ◽

Vol 45 ◽

pp. 2332-2336

Author(s):

Ki Hyun Yoon ◽

Ji Won Choi

Keyword(s):

Thin Films ◽

Dielectric Constant ◽

Thermal Expansion ◽

Thermal Stress ◽

Dielectric Properties ◽

Dielectric Loss ◽

Microwave Dielectric Properties ◽

Mixing Rule ◽

Microwave Dielectric ◽

Dielectric Layers

The microwave dielectric properties of (300-X) nm MgTiO3/(X) nm CaTiO3 thin films have been investigated with correlation between the interface and stress induced by dielectric layers with heattreatment. As the thickness (X) of CaTiO3 film increased, the dielectric constant increased and the temperature coefficient of the dielectric constant changed from the positive to the negative values by the dielectric mixing rule. The dielectric loss of (300-X) nm MgTiO3/(X) nm CaTiO3 thin films increased with an increase of the thickness (X) of CaTiO3 film because of higher thermal stress induced by the higher thermal expansion coefficient of CaTiO3 than that of MgTiO3.

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