研究目的
To synthesize (Ag1/4Ta3/4)0.005Ti0.995O2 ceramics with low dielectric loss, high dielectric constant, and good temperature stability by modulating sintering conditions, aiming to achieve properties superior to commercial X9R capacitors.
研究成果
The (Ag1/4Ta3/4)0.005Ti0.995O2 ceramics synthesized at 1330 °C for 10 h exhibit a giant dielectric constant (~9831 at 1 kHz), low dielectric loss (~0.041 at 1 kHz), and excellent temperature stability with a coefficient within -6.8% to 8.8% from -200 to 200 °C at 10 kHz, surpassing commercial X9R capacitor requirements. This suggests high potential for microelectronics applications, with future work needed to optimize for higher temperatures and explore other dopants.
研究不足
The study is limited to specific co-doping with Ag+ and Ta5+ in TiO2 ceramics; other dopants or synthesis methods were not explored. The temperature range for stability is up to 200 °C, beyond which dielectric constant increases dramatically, indicating potential issues at higher temperatures. The mechanisms, such as space charge polarization, are inferred but not fully validated.
1：Experimental Design and Method Selection:
The conventional solid phase method was used for synthesis, based on the electron pinned defect dipole (EPDD) mechanism to explain dielectric behavior.
2：Sample Selection and Data Sources:
Ceramics were prepared with raw materials TiO2 (rutile), Ta2O5, and Ag2O, weighed according to stoichiometric ratios.
3：List of Experimental Equipment and Materials:
Equipment included a tube furnace for sintering, Rigaku D/max–2550/PC diffractometer for XRD, SEM (Quanta 200, FEI Co.) for morphology, LCR HiTESTER (HIOKI 3532-50) for dielectric measurements, and precision impedance analyzer (4294A, Agilent) for dispersion spectra. Materials included ethanol for ball milling, polyvinyl alcohol for granulation, and silver paint for electrode coating.
4：Experimental Procedures and Operational Workflow:
Steps involved ball milling in ethanol, drying at 80 °C, calcination at 1100 °C for 3 h, granulation with PVA, pressing into wafers, sintering at 1290–1340 °C for 5–20 h, polishing, coating with silver paint, calcining at 850 °C, and measuring dielectric properties.
5：Data Analysis Methods:
XRD patterns were analyzed with Rietveld refinement using GASA, density measured via Archimedes' principle, SEM for microstructure, and dielectric data analyzed for temperature and frequency dependence.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
