Preparation of La-doped SrTiO3 ceramics with colossal permittivity and high insulation resistivity via controlling the particle diameters of the powders

• Published in: Ceramics international 2024-12, Vol.50 (24), p.54232-54239
• Main Authors: Zhuo, Weizhuang, Li, Shanshan, He, Xuming, Hou, Bo, Wen, Weijia
• Format: Article
• Language: English
• ISSN: 0272-8842
• DOI: 10.1016/j.ceramint.2024.10.280

Ceramic capacitors are widely studied and applied in the electronic industry. We utilized the sand-milling technique to produce a series of La-doped SrTiO3 powders with varying particle diameters and investigated the effect of particle size on the resulting dielectric properties for the first time. We found that reducing the particle diameter significantly enhances the permittivity from approximately 7000 to 32000 (at 1 kHz, room temperature). Furthermore, a colossal permittivity of ∼32000 (at 1 kHz, room temperature), combined with ultra-high resistivity (>7 × 1011 Ω cm), low loss (0.004), and excellent frequency/temperature stability, were simultaneously achieved in the ceramic. Lastly, the sintering temperature is as low as 1360 °C, making it suitable for industrial production. By analyzing scanning electron microscopy (SEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) results, we discuss the possible mechanism behind the enhancement of permittivity with increased sand-milling time. The low sintering temperature and highly controllable permittivity of the ceramics by adjusting the sand-milling time of the powders offer a new strategy for the scientific study and industrial application of materials with colossal permittivity.