Electrical transport in lead-free Na0.5Bi0.5TiO3 ceramics

• DOI: 10.1007/s40145-020-0430-5
• Publication Date: 2021-01-18T17:04:48Z
• Authors: J. Suchanicz; K. Kluczewska-Chm...; D. Sitko; G. Jagło
• Keywords: impedance spectroscopy; TP785-869; Na0.5Bi0.5TiO3 (NBT) ceramics; electrical properties; 0103 physical sciences; Clay industries. Ceramics. Glass; Seebeck coefficient; 01 natural sciences

Abstract Lead-free Na 0.5 Bi TiO 3 (NBT) ceramics were prepared via a conventional oxide-mixed sintering route and their electrical transport properties investigated. Direct current (DC, σ DC ) alternating (AC, AC conductivity values, polarization (first measurements) depolarization current, current–voltage ( I – U characteristics measurements), the Seebeck coefficient (α) determined under various conditions. The mechanism of phenomena observed for investigated samples found to be typical. For low voltages, in good agreement with Ohm’s law; higher dependences 2 , 4 then 6 . low-frequency followed formula –ω s (ω is angular frequency exponent). exponent was equal 0.18–0.77 0.73–0.99 low- high-frequency regions, respectively, decreased temperature increasing. It shown that conduction mechanisms involved hopping charge carriers at temperatures, small polarons intermediate oxygen vacancies high temperatures. Based on data, density states Fermi-level, minimum length estimated. Electrical undergo p–n–p transitions increasing temperature. These occurred T d 280 ℃, maximum electric permittivity m as typical NBT materials.