Effects of sintering condition on giant dielectric and nonlinear current-voltage properties of Na1/2Y1/2Cu3Ti3.975Ta0.025O12 ceramics

Pariwat Saengvong; Jakkree Boonlakhorn; Jutapol Jumpatam; Narong Chanlek; Jariyanee Prasongkit; Bundit Putasaeng; Pairot Moontragoon; Pornjuk Srepusharawoot; Prasit Thongbai

doi:10.1016/j.heliyon.2023.e12946

Effects of sintering condition on giant dielectric and nonlinear current-voltage properties of Na_1/2Y_1/2Cu₃Ti_3.975Ta_0.025O₁₂ ceramics

Heliyon. 2023 Jan 14;9(1):e12946. doi: 10.1016/j.heliyon.2023.e12946. eCollection 2023 Jan.

Authors

Pariwat Saengvong¹, Jakkree Boonlakhorn², Jutapol Jumpatam³, Narong Chanlek⁴, Jariyanee Prasongkit⁵, Bundit Putasaeng⁶, Pairot Moontragoon¹, Pornjuk Srepusharawoot¹, Prasit Thongbai¹

Affiliations

¹ Giant Dielectric and Computational Design Research Group (GDCDR), Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
² Department of Basic Science and Mathematics, Faculty of Science, Thaksin University, Songkhla Campus, Songkhla, 90000, Thailand.
³ Department of Fundamental Science, Faculty of Science and Technology, Surindra Rajabhat University, Surin, 32000, Thailand.
⁴ Synchrotron Light Research Institute (Public Organization), 111 University Avenue, Muang District, Nakhon Ratchasima, 30000, Thailand.
⁵ Division of Physics, Faculty of Science, Nakhon Phanom University, Nakhon Phanom, 48000, Thailand.
⁶ National Metal and Materials Technology Center, National Science and Technology Development Agency, Thailand Science Park, Pathum Thani, 12120, Thailand.

Abstract

The effects of sintering conditions on the microstructure, giant dielectric response, and electrical properties of Na_1/2Y_1/2Cu₃Ti_3.975Ta_0.025O₁₂ (NYCTTaO) were studied. A single phase of Na_1/2Y_1/2Cu₃Ti₄O₁₂ and a high density (>98.5%) were obtained in the sintered NYCTTaO ceramics. First-principles calculations were used to study the structure of the NYCTTaO. Insulating grain boundaries (i-GBs) and semiconducting grains (semi-Gs) were studied at different temperatures using impedance and admittance spectroscopies. The conduction activation energies of the semi-Gs and i-GBs were E_g ≈ 0.1 and E_gb ≈ 0.6 eV, respectively. A large dielectric constant (ε' ≈ 2.43-3.89 × 10⁴) and low loss tangent (tanδ ≈ 0.046-0.021) were achieved. When the sintering temperature was increased from 1070 to 1090 °C, the mean grain size slightly increased, while ε' showed the opposite tendency. Furthermore, the breakdown electric field (E_b) increases significantly. As the sintering time increased from 5 to 10 h, the mean grain size did not change, whereas ε' and E_b increased. Variations in the dielectric response and non-linear electrical properties were primarily described by the intrinsic (E_gb) and extrinsic (segregation of Na-, Cu-, Ta-, and O-rich phases) properties of the i-GBs based on the internal barrier layer capacitor effect.

Keywords: First principle calculations; Giant dielectric properties; Maxwell−Wagner polarization; Microstructure; NYCTO.