Origins of high–performance giant dielectric properties in TiO2 co-doped with aliovalent ions via broadband dielectric spectroscopy

Abstract

(Zn1/3Ta2/3)xTi1-xO2 ceramics with x = 0.01 (ZnTTO-1 %) and x = 0.1 (ZnTTO-10 %) were prepared by a solid-state reaction method. Remarkably, the ZnTTO-1 % and ZnTTO-10 % ceramics sintered at 1500 °C for 2 h showed a high dielectric permittivity of approximately 3.90 × 104 and 6.23 × 104 at 1 kHz with low tanδ values of 0.014 and 0.024, respectively. Furthermore, the ZnTTO-1 % ceramic exhibited good temperature stability with a temperature coefficient of <±15 % in the temperature range of 218–473 K (−55–200 °C), which meets the requirement of the X9R capacitor application. The dielectric relaxations in the wide temperature range of 15–483 K was attained using broadband dielectric spectroscopy to clarify the sources of the excellent dielectric properties. The best performance was demonstrated in the ZnTTO-1 % ceramic. The electron pin defect dipole mechanism, electron hopping, and interface effects are attributed to the giant dielectric responses.

Keywords

• Colossal/Giant dielectric permittivity
• Broadband dielectric spectroscopy
• X-ray photoelectron spectroscopy
• Rutile TiO2