Microwave characteristics of mixed phases of BaTi4O9-BaPr2Ti4O12 ceramics

Fukuda, Koichi; Kitoh, Ryozo; Awai, Ikuo

doi:10.1007/bf00356121

Cited by 18 publications

(5 citation statements)

References 14 publications

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“…Several authors [63,64,[70][71][72][73][74][75] analyzed the FIR reflectivity data using K-K analysis and classical dispersion theory and estimated the permittivity and dielectric loss tangent. There is reasonable agreement between the " r obtained by the spectroscopic method and that measured by microwave methods.…”

Section: Estimation Of Dielectric Loss By Spectroscopic Methodsmentioning

confidence: 99%

Measurement of Microwave Dielectric Properties and Factors Affecting Them

Sebastian

2008

Dielectric Materials for Wireless Communication

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Section: Estimation Of Dielectric Loss By Spectroscopic Methodsmentioning

confidence: 99%

Measurement of Microwave Dielectric Properties and Factors Affecting Them

Sebastian

2008

Dielectric Materials for Wireless Communication

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“…The composition range of the solid solutions becomes narrower with the decrease in the ionic radius of the R-ion, and Ga and Eu form only BaO•R 2 O 3 •4TiO 2 composition [44]. [46]. On the solid solutions, the composition with x = 2/3 was found by Ohsato et al [42], at which the Qf value becomes the highest due to the ordering in the rhombic and pentagonal sites.…”

Section: Conclusion For Indialite/cordierite Glass Ceramicsmentioning

confidence: 99%

Dielectric Losses of Microwave Ceramics Based on Crystal Structure

Ohsato¹,

Varghese²,

Jantunen³

2020

Electromagnetic Materials and Devices

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So far, many microwave dielectric materials have been investigated for a range of telecommunication applications. In dielectrics, the three main dielectric properties are quality factor (Q), dielectric constant and temperature coefficient of resonant frequency. Among these, the most essential dielectric property is Q. More specifically, Q is the inverse of the dielectric loss (tanδ); thus Q = 1/tanδ. There are two kinds of losses: those depending on crystal structure and losses due to external factors. The former is intrinsic losses such as ordering, symmetry, and phonon vibration. The latter is extrinsic losses due to factors such as grain size, defects, inclusions and distortion. In this chapter, the authors present the origin of dielectric losses based on the crystal structure. An ideal and well-proportional crystal structure constitutes a low loss material. Most dielectric materials are paraelectrics with inversion symmetry i and high symmetry. In general, it is believed that ordering gives rise to a high Q, on which many researchers are casting doubt. In the case of complex perovskites, the symmetry changes from cubic to trigonal. Ordering and symmetry should be compared with the structure. In this chapter, three essential conditions for the origin of high Q such as high symmetry, compositional ordering and compositional density are presented.

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“…One is TiO 2 -Bi 2 Ti 4 O 11 ceramic 4 and the other is BaTi 4 O 9 -BaPr 2 Ti 4 O 12 ceramic. 5 The backscattering electron images (SEM images) of these ceramics are shown in Figs. 5 and 6, respectively.…”

Section: Microstructure Of Tio 2 -Bi 2 Ti 4 O 11 and Bati 4 O 9 -mentioning

confidence: 99%

Determination of the Temperature Coefficient Distribution of Dielectric Ceramics Using Scanning Photothermal Dielectric Microscopy

Cho

Kasahara

Fukuda

1999

Journal of the American Ceramic Society

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11 grains had negative and positive temperature coefficients, respectively, and that the macroscopic averaged temperature coefficient of the ceramic was relatively low because of the cancellation of the opposite signs of the coefficients. On the other hand, the images of the BaTi 4 O 9 -BaPr 2 Ti 4 O 12 ceramic showed that the temperature coefficient of both grains had the same sign (negative), although their absolute values were quite different.

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Microwave characteristics of mixed phases of BaTi4O9-BaPr2Ti4O12 ceramics

Cited by 18 publications

References 14 publications

Measurement of Microwave Dielectric Properties and Factors Affecting Them

Measurement of Microwave Dielectric Properties and Factors Affecting Them

Dielectric Losses of Microwave Ceramics Based on Crystal Structure

Determination of the Temperature Coefficient Distribution of Dielectric Ceramics Using Scanning Photothermal Dielectric Microscopy

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