High-performance colossal permittivity materials of (Nb + Er) co-doped TiO2 for large capacitors and high-energy-density storage devices

• Published in: Physical chemistry chemical physics : PCCP 2016-01, Vol.18 (35), p.24270-24277
• Main Authors: Tse, Mei-Yan, Wei, Xianhua, Hao, Jianhua
• Format: Article
• Language: English
• Subjects: Capacitors; Dielectric constant; Dielectric loss; Energy storage; Erbium; Niobium; Permittivity; Titanium dioxide
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c6cp02236g

The search for colossal permittivity (CP) materials is imperative because of their potential for promising applications in the areas of device miniaturization and energy storage. High-performance CP materials require high dielectric permittivity, low dielectric loss and relatively weak dependence of frequency- and temperature. In this work, we first investigate the CP behavior of rutile TiO2 ceramics co-doped with niobium and erbium, i.e., (Er0.5Nb0.5)xTi1-xO2. Excellent dielectric properties were observed in the materials, including a CP of up to 10(4)-10(5) and a low dielectric loss (tan δ) down to 0.03, which are lower than that of the previously reported co-doped TiO2 CP materials when measured at 1 kHz. Stabilities of frequency and temperature were also accomplished via doping Er and Nb. Valence states of the elements in the material were analyzed using X-ray photoelectron spectroscopy. The Er induced secondary phases were observed using elemental mapping and energy-dispersive spectrometry. Consequently, this work may provide comprehensive guidance to develop high-performance CP materials for fully solid-state capacitor and energy storage applications.