Effect of two-step sintering on the microwave dielectric properties of Zn1.8SiO3.8 ceramics

Eoh, Young Jun; Ahn, Hong Jun; Kim, Eung Soo

doi:10.1016/j.ceramint.2015.03.151

Cited by 9 publications

(6 citation statements)

References 23 publications

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“…And it is dominated by the secondary phase, microstructural characteristics, centro‐symmetry of hexagonal ring and packing fraction [35,36] . Compared with x =0–0.04, the appearance of liquid phase result in the decrease of Qf values at x ≥0.12 from SEM images (Figures 5(a–c)) [4,37] . According to XRD pattern (Figure 1), the secondary phases are MgAl 2 O 4 (0≤ x ≤0.08) and Al 2 SiO 5 (0.08< x ≤0.16).…”

Section: Resultsmentioning

confidence: 98%

“…[35,36] Compared with x = 0-0.04, the appearance of liquid phase result in the decrease of Qf values at x � 0.12 from SEM images (Figures 5(a-c)). [4,37] According to XRD pattern (Figure 1), the secondary phases are MgAl 2 O 4 (0 � x � 0.08) and Al 2 SiO 5 (0.08 < x � 0.16). The Qf values exhibit the decreasing trend, because the Qf values of MgAl 2 O 4 (Qf~68,900 GHz) [31] are higher than that of Al 2 SiO 5 (Qf~41,800 GHz).…”

Section: Resultsmentioning

confidence: 99%

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Enhanced Microwave Dielectric Properties in Mg₂Al₄Si₅O₁₈ Through Cu²⁺ Substitution

et al. 2021

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The Mg 2 Al 4 Si 5 O 18 ceramic is considered as a kind of important candidates for millimeter-wave applications. In this work, Mg 2x Cu x Al 4 Si 5 O 18 (0 � x � 0.16) ceramics were synthesized by solidstate reaction, aiming to improve the microwave dielectric properties. According to the X-ray powder diffraction (XRD) analysis, Cu 2 + ions enter into the Mg 2 Al 4 Si 5 O 18 lattice and form a solid solution. The dense microstructure was observed in the Cu-substituted Mg 2 Al 4 Si 5 O 18 ceramics at x = 0.04 sintered at 1420°C. The dielectric constant (ɛ r ) values depend on the microstructure, secondary phase and ionic polarizability of the samples. The quality factor (Qf) values are dominated by the microstructure, secondary phase and centro-symmetry of [Si 4 Al 2 ] hexagonal ring. The temperature coefficients of resonance frequency (τ f ) are strongly related to the Mg/CuÀ O bond valance. In comparison to pure Mg 2 Al 4 Si 5 O 18 ceramics, the excellent microwave dielectric properties with ɛ r = 4.56, Qf = 31,100 GHz and τ f = À 52 ppm/°C were obtained at x = 0.04 with sintering at 1420°C. Thus, the Mg 2-x Cu x Al 4 Si 5 O 18 (0 � x � 0.16) ceramics will be promising millimeter-wave communication materials.

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Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Enhanced Microwave Dielectric Properties in Mg₂Al₄Si₅O₁₈ Through Cu²⁺ Substitution

et al. 2021

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“…9,[36][37][38] Additionally, employing non-stoichiometric ratios in traditional solid-state methods effectively eliminates the second phase ZnO. [39][40][41] Zn 1.8 SiO 3.8 ceramics exhibit excellent microwave performance when sintered at 1 300 • C, with ε r = 6.6, Q×f = 147 000 GHz and τ f = −22 ppm/ • C. 42 On the other hand, the high sintering temperature and large temperature coefficient are the main barriers. The high sintering temperature can be lowered by adding sintering aids such as glass powders or low-melting-point oxides but at the expense of the quality factor.…”

Section: Introductionmentioning

confidence: 99%

Phase purifying and dielectric improvement in Zn₂SiO₄ ceramics via simply controlling the particle size of SiO₂

Xing,

Song,

Pan

2024

Int J Applied Ceramic Tech

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The zinc orthosilicate, Zn2SiO4 ceramics, exhibit great potential as microwave dielectric materials due to their low dielectric constant and ultrahigh quality factor. The solid‐state synthesis of Zn2SiO4 ceramics often results in the presence of a secondary phase of ZnO, however, leading to significantly lower Q×f values. Cold‐isostatic‐pressing (CIP) and nonstoichiometry have been proven effective in purifying the Zn2SiO4 but need elaborate process and composition manipulation. In this work, it was found that the particle size of SiO2 plays a crucial role in purifying the Zn2SiO4 phase. Specially, nano‐sized SiO2 particles (15 and 30 nm) led to the formation of a ZnO secondary phase in synthesized Zn2SiO4 ceramics, while micro‐sized (2 and 10 µm) resulted in pure‐phase Zn2SiO4 with excellent microwave properties. Notably, when prepared with 10 µm SiO2 and sintered at 1 340°C, the resulting Zn2SiO4 exhibited outstanding microwave performances with a Q×f value of 122 570 GHz, a temperature coefficient of frequency τf of −51.9 ppm/°C, and a dielectric constant (εr) of 6.5. These findings highlight the importance of controlling particle size during synthesis to achieve desired material properties such as purity and excellent microwave performances.

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“…The dielectric resonator generally uses the frequency of a certain vibration mode of dielectric ceramic as its center frequency. Therefore, in order to eliminate the temperature drift of the resonant frequency characteristic of the resonator, it is necessary to make the TCF close to zero …”

Section: Introductionmentioning

confidence: 99%

“…Therefore, in order to eliminate the temperature drift of the resonant frequency characteristic of the resonator, it is necessary to make the TCF close to zero. [1][2][3][4][5][6][7] In 2000, Valant and Suvorov 8 first reported that BiVO 4 ceramic not only sinter at a low temperature (<900°C) but also exhibit excellent microwave dielectric properties, with a permittivity (ε r ) of ~68, a Qf (Q = quality factor = 1/dielectric loss; f = resonant frequency) value of ~6500 GHz, and a negative TCF of ~−260 ppm/°C. However, the large negative TCF will limit its application in microwave devices, thus, further studies to adjust the TCF of BiVO 4 ceramic to near zero are of great interest.…”

Section: Introductionmentioning

confidence: 99%

Microwave dielectric properties of temperature‐stable zircon‐type (Bi, Ce)VO₄ solid solution ceramics

et al. 2019

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In the (Bi1 − xCex)VO4 (0 ≤ x ≤ 1) system, we found that the (Bi1 − xCex)VO4 (0 ≤ x ≤ 0.1) belongs to the monoclinic scheelite phase and the (Bi1 − xCex)VO4 (0.7 ≤ x ≤ 1) belongs to the tetragonal zircon phase, while the (Bi1 − xCex)VO4 (0.1 < x < 0.7) belongs to the mixed phases of both monoclinic scheelite and tetragonal zircon structure. Interestingly, two components with near‐zero temperature coefficient of resonant frequency (TCF) appeared in this system. In our previous work, a near‐zero TCF of ~+15 ppm/°C was obtained in a (Bi0.75Ce0.25)VO4 ceramic with a permittivity (εr) of ~47.9 and a Qf (Q = quality factor = 1/dielectric loss; f = resonant frequency) value of ~18 000 GHz (at 7.6 GHz). Furthermore, in the present work, another temperature‐stable microwave dielectric ceramic was obtained in (Bi0.05Ce0.95)VO4 composition sintered at 950°C and exhibits good microwave dielectric properties with a εr of ~11.9, a Qf of ~22 360 GHz (at 10.6 GHz), and a near‐zero TCF of ~+6.6 ppm/°C. The results indicate that this system might be an interesting candidate for microwave device applications.

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Effect of two-step sintering on the microwave dielectric properties of Zn1.8SiO3.8 ceramics

Cited by 9 publications

References 23 publications

Enhanced Microwave Dielectric Properties in Mg₂Al₄Si₅O₁₈ Through Cu²⁺ Substitution

Enhanced Microwave Dielectric Properties in Mg₂Al₄Si₅O₁₈ Through Cu²⁺ Substitution

Phase purifying and dielectric improvement in Zn₂SiO₄ ceramics via simply controlling the particle size of SiO₂

Microwave dielectric properties of temperature‐stable zircon‐type (Bi, Ce)VO₄ solid solution ceramics

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Effect of two-step sintering on the microwave dielectric properties of Zn1.8SiO3.8 ceramics

Cited by 9 publications

References 23 publications

Enhanced Microwave Dielectric Properties in Mg2Al4Si5O18 Through Cu2+ Substitution

Enhanced Microwave Dielectric Properties in Mg2Al4Si5O18 Through Cu2+ Substitution

Phase purifying and dielectric improvement in Zn2SiO4 ceramics via simply controlling the particle size of SiO2

Microwave dielectric properties of temperature‐stable zircon‐type (Bi, Ce)VO4 solid solution ceramics

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Enhanced Microwave Dielectric Properties in Mg₂Al₄Si₅O₁₈ Through Cu²⁺ Substitution

Enhanced Microwave Dielectric Properties in Mg₂Al₄Si₅O₁₈ Through Cu²⁺ Substitution

Phase purifying and dielectric improvement in Zn₂SiO₄ ceramics via simply controlling the particle size of SiO₂

Microwave dielectric properties of temperature‐stable zircon‐type (Bi, Ce)VO₄ solid solution ceramics