Properties of (1-x)NaCu₃Ti₃NbO₁₂-(x)BaTiO₃ ceramics with various sintering temperatures prepared by conventional solid-state reaction method

ABSTRACT

In the research, the properties of sodium copper titanate niobate – barium titanate [(1-x)NaCu₃Ti₃NbO₁₂-(x)BaTiO₃: (1-x)NCTNO-(x)BT] ceramics prepared by conventional solid-state reaction method with various molecular weight of BT or x between 0.1, 0.3 and 0.5 were investigated. These ceramics were sintered at 975, 1000, 1025 and 1050 ^oC for 10 h in ambient atmosphere. The phase structure, microstructure, density, micro-hardness and dielectric properties were examined by x-ray diffraction technique (XRD), scanning electron microscopy (SEM), Archimedes method, Vickers micro-hardness tester and impedance analyzer, respectively. It was found that, the addition of BaTiO₃ resulted in the formation of second phase which increased upon increasing the BaTiO₃ content. Compared to the base composition, the grain sizes of all the (1-x)NCTNO-(x)BT were significantly reduced. The densities of (1-x)NCTNO-(x)BT ceramics and dielectric properties were improved with the addition of BaTiO₃. For the effect of sintering temperatures, no substantial change in the crystal structure and grain growth was found whereas an increase in densities and hardness with increasing temperatures were observed. The (0.7)NCTNO-(0.3)BT ceramics sintered at 1025 ^oC showed the highest density and dielectric constant (∼80500) at room temperature with 1 kHz measurement.

KEYWORDS:

• (1-x)NaCu₃Ti₃NbO₁₂-(x)BaTiO₃ ceramics
• solid-state reaction method
• dielectric constant
• sintering temperature

Acknowledgment

The author would like to thank Prof. Dr. Tawee Tunkasiri for his help in many facilities (Materials Science Research Laboratory (MSRL), Department of Physics and Materials Science, Chiang Mai University).

Additional information

Funding

This work was supported by National Research Council of Thailand (NRCT), Department of Physics, Faculty of Science, Naresuan University.