Millimeter-wave Dielectric Properties of Titanite-based Ceramics.

Andou, Minato; Higashida, Yutaka; Okuma, Hideo

doi:10.2497/jjspm.50.86

Cited by 3 publications

(4 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Expecting such effects this procedure was also applied to titanite ceramics in order to increase and enhance loss tangent of titanite: A titanite-based ceramics with nominal composition CaTi 1−x Zr x SiO 5 (0 x 0.5) was fabricated where a part of Ti in pure titanite was replaced by Zr. It was confirmed that it had both far higher relative permittivity and dielectric loss tangent compared to those of a pure titanite 5) , A similar effect may be expected also for CaTi…”

Section: Introductionsupporting

confidence: 70%

Millimeter-wave Dielectric Properties of Titanite-based Ceramics with Nominal Composition CaTi1-xNb4x/5SiO5

Ando¹,

Higashida²

2020

J. Jpn. Soc. Powder Powder Metallurgy

Self Cite

View full text Add to dashboard Cite

The titanite-based ceramics with nominal composition CaTi 1−x Nb 4x/5 SiO 5 (0 x 0.2) in which part x of Ti sites are occupied with Nb, showed a remarkable jump of the complex relative permittivity at x = 0.025 compared with that at x = 0 at 110 GHz. Real part increased from 22.5 to 39, and the imaginary part from 4 to 14 (tangent delta from 0.18 to 0.36). Non-reflection condition is fulfilled in both cases when 0 < x < 0.0125, d/λ 0 = 0.05 and x = 0.2, d/λ 0 = 0.045, where d is thickness of the plate sample and λ 0 is the wavelength of incident electromagnetic wave. The dominant dielectric dispersion may occurr due to difference of ionic polarization between Ti 4+ and Nb 5+ ions relative to O 2− ions, which becomes inactive and saturates at x = 0.025. From the measurement of the lattice parameters, a, b, c, and the angle β, characterizing monoclinic crystal structure, this saturation may have close correlation with some structural rearrangement of constituting atoms, Ti and Nb in CaTi 1−x Nb 4x/5 SiO 5 .

show abstract

Section: Introductionsupporting

confidence: 70%

Millimeter-wave Dielectric Properties of Titanite-based Ceramics with Nominal Composition CaTi1-xNb4x/5SiO5

Ando¹,

Higashida²

2020

J. Jpn. Soc. Powder Powder Metallurgy

Self Cite

View full text Add to dashboard Cite

show abstract

“…Then the synthesized specimen for x < 0.2 is considered to constitute a substitutional solid solution where part of Ti site is occupied by added Nb atoms. The dominant crystal phase and minority crystal phases for all the synthesized specimens are summarized in Table 3 above [5,7]. Figs.11,12,and 13 shows the lattice parameters a, b, c, the lattice volume, and the angle β between a and c axis.…”

Section: Resultsmentioning

confidence: 99%

“…Expecting such effects this procedure was also applied to titanite ceramics in order to increase and enhance loss tangent of titanite. A titanite-based ceramics with nominal composition CaTi1-xMySiO5 (0≦x≦1, y = x for M = Mn, Sn, Zr) was fabricated where a part of Ti in pure titanite was replaced by another atom M. It was confirmed that CaTi1-xZrxSiO5 had far higher relative permittivity and dielectric loss tangent compared to those of a pure titanite [5,6]. A similar effect was obtained also for CaTi1-xNbySiO5 ( y = 4x/5) with part of Ti sites replaced by Nb having nearly the same atomic radius as Ti but having valence 5 different only by 1 from Ti [7].…”

Section: Introductionmentioning

confidence: 88%

“…Crystalline phases were analyzed by powder X-ray diffraction (XRD) using Cu Kα radiation with scanning width 0.02 degree of reflection angle 2θ. The 002), ( 031), (131), and (140), of monoclinic crystal system [5,7] . The dielectric properties of the sample were measured using Hakki's and Coleman's method for low loss sample about 20 GHz and for lossy sample using free space method from 50 to 110 GHz after polishing both faces of the sample into the thickness of 2 mm [9,10].…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Lossy Titanite-Based Ceramics with Nominal Compositions CaTi1-xMySiO 5 (0 ≦ X, Y ≦ 1, M = Mn, Sn, Zr, Nb) Applicable to Millimeter Electromagnetic Wave Absorber

Higashida¹,

Ando²

2021

KEM

Self Cite

View full text Add to dashboard Cite

The titanite-based ceramics with nominal composition CaTi1-xMySiO5 (0≦x≦1, M = Mn, Sn, Zr (y = x), and M = Nb (y = 4x/5)) in which part x of Ti sites are replaced by several kinds of atoms had remarkable increase in both the real and imaginary parts of complex relative permittivity around x = 0.0125~0.1 compared with those of pure titanite CaTiSiO5 ( x = 0) at 70 GHz. Real part varied from 3 to 43, and the imaginary part from 0 to 12 (tangent delta from 0 to 0.28). No reflection condition is fulfilled for M = Zr when x = 0.05, d/λ0 =0.042, and for M = Nb in both cases when 0 < x < 0.0125, d/λ0 = 0.05 and 0.1 <x < 0.2, d/λ0 =0.042, where d is thickness of the plate sample and λ0 is the wavelength of incident electromagnetic wave. The dominant dielectric dispersion may occur due to difference of ionic polarization between Ti4+ ions and Mn4+, Sn4+, Zr4+, or Nb5+ ions relative to O2- ions, which becomes inactive and saturates around x = 0.0125~0.05. From the measurement of the lattice parameters, a, b, c, and the angle β, characterizing monoclinic crystal structure, this saturation may have close correlation with some structural rearrangement of constituting atoms, Ti and substituted M atoms in CaTi1-xMySiO5

show abstract

Functional advances of microwave dielectrics for next generation

Ohsato

2012

Ceramics International

View full text Add to dashboard Cite

Millimeter-wave Dielectric Properties of Titanite-based Ceramics.

Cited by 3 publications

References 2 publications

Millimeter-wave Dielectric Properties of Titanite-based Ceramics with Nominal Composition CaTi<sub>1-<i>x</i></sub>Nb<sub>4<i>x</i>/5</sub>SiO<sub>5</sub>

Millimeter-wave Dielectric Properties of Titanite-based Ceramics with Nominal Composition CaTi<sub>1-<i>x</i></sub>Nb<sub>4<i>x</i>/5</sub>SiO<sub>5</sub>

Lossy Titanite-Based Ceramics with Nominal Compositions CaTi<sub>1-</sub><i><sub>x</sub></i>M<i><sub>y</sub></i>SiO <sub>5</sub> (0 ≦ <i>X</i>, <i>Y </i>≦ 1, M = Mn, Sn, Zr, Nb) Applicable to Millimeter Electromagnetic Wave Absorber

Functional advances of microwave dielectrics for next generation

Contact Info

Product

Resources

About