Lead-free Na_0.5Bi_0.5TiO₃ (NBT) ceramics were prepared via a conventional oxide-mixed sintering route and their electrical transport properties were investigated. Direct current (DC, σ_DC) and alternating current (AC, σ_AC) electrical conductivity values, polarization current (first measurements) and depolarization current, current–voltage (I–U) characteristics (first measurements), and the Seebeck coefficient (α) were determined under various conditions. The mechanism of depolarization and the electrical conductivity phenomena observed for the investigated samples were found to be typical. For low voltages, the I–U characteristics were in good agreement with Ohm’s law; for higher voltages, the observed dependences were I–U², I–U⁴, and then I–U⁶. The low-frequency σ_AC followed the formula σ_AC–ω^s (ω is the angular frequency and s is the frequency exponent). The exponent s was equal to 0.18–0.77 and 0.73–0.99 in the low- and high-frequency regions, respectively, and decreased with temperature increasing. It was shown that conduction mechanisms involved the hopping of charge carriers at low temperatures, small polarons at intermediate temperatures, and oxygen vacancies at high temperatures. Based on AC conductivity data, the density of states at the Fermi-level, and the minimum hopping length were estimated. Electrical conduction was found to undergo p–n–p transitions with increasing temperature. These transitions occurred at depolarization temperature T_d, 280 ℃, and temperature of the maximum of electric permittivity T_m is as typical of NBT materials.

采用常规的氧化物混合烧结法制备了无铅Na _0.5 Bi _0.5 TiO ₃（NBT）陶瓷，并研究了其电传输性能。直流（DC，σ _DC）和交流（AC，σ _AC）导电性值，极化电流（第一测量结果）和去极化电流，电流-电压（我- Û）特性（第一测量结果），和塞贝克系数（ α）是在各种条件下确定的。发现对所研究样品观察到的去极化机理和电导率现象是典型的。对于低电压，I – U特性符合欧姆定律；对于更高的电压，观察到的相关性是I – U ²，I – U ⁴，然后是I – U ⁶。低频σ _AC遵循公式σ _AC -ω^小号（ω是角频率和š是频率指数）。该指数小号在低频和高频区域分别等于0.18–0.77和0.73–0.99，并且随着温度升高而降低。结果表明，传导机制涉及低温下电荷载流子的跳跃，中等温度下的小极化子和高温下的氧空位。根据交流电导率数据，估算费米能级的状态密度和最小跳变长度。人们发现，随着温度的升高，电导会经历p–n–p跃迁。这些转变发生在去极化温度T _d，280℃，并且最大电容率T _m的温度是NBT材料的典型特征。