Microwave Dielectric Behavior of CoTiTa<sub>2</sub>O<sub>8</sub>-MgNb<sub>2</sub>O<sub>6</sub> Composite Ceramics: A Focus on Temperature Stability and Compositional Effects
Microwave dielectric (1 − x)CoTiTa<sub>2</sub>O<sub>8</sub>-xMgNb<sub>2</sub>O<sub>6</sub> composite ceramics (x = 0.625–0.725) were fabricated through a two-step method and sintering techniques. The applied CoTiTa<sub>2</sub>O<sub>8&...
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| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-04-01
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| Series: | Metals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-4701/15/4/407 |
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| Summary: | Microwave dielectric (1 − x)CoTiTa<sub>2</sub>O<sub>8</sub>-xMgNb<sub>2</sub>O<sub>6</sub> composite ceramics (x = 0.625–0.725) were fabricated through a two-step method and sintering techniques. The applied CoTiTa<sub>2</sub>O<sub>8</sub> and MgNb<sub>2</sub>O<sub>6</sub> powders were both synthesized by calcining stoichiometric mixtures of their respective metal oxides at 1000 °C for 3 h. The optimal sintering parameters were determined using visual high-temperature deformation analysis. The influence of the MgNb<sub>2</sub>O<sub>6</sub> content on the phase composition, microstructure, and microwave dielectric properties of the obtained composite ceramics was comprehensively investigated. It was observed that an increase in the MgNb<sub>2</sub>O<sub>6</sub> content resulted in a reduction in the dielectric constant (ε<sub>r</sub>) and a significant enhancement in the quality factor (Q × <i>f</i>). The ceramics with a compositional value of x = 0.675, sintered at 1193 °C for 4.5 h, demonstrated a near-zero temperature coefficient of the resonant frequency (τ<i><sub>f</sub></i>), exhibiting optimal microwave dielectric properties: ε<sub>r</sub> = 28.4, Q × <i>f</i> = 33,055 GHz, and τ<i><sub>f</sub></i> = −3.1 ppm/°C. These findings underscore the potential of the present CoTiTa<sub>2</sub>O<sub>8</sub>-MgNb<sub>2</sub>O<sub>6</sub> composite ceramics for advanced microwave applications. |
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| ISSN: | 2075-4701 |