| 초록 |
To improve the strain properties of Bi–based lead–free ceramics at low electric fields, ferroelectric 0.995Bi0.5Na0.41K0.09TiO3–0.005BaZrO3 (0.5BZ) seed particles were embedded in 0.98Bi0.5Na0.39K0.11TiO3–0.02LaFeO3 (2LF) relaxor ceramic using a conventional solid–state reaction. The unipolar strain versus electric field hysteresis loops of the ferroelectric/relaxor 0.5BZ/2LF composites resulted in a maximum Smax/Emax of 513 and 707 pm/V at 3 and 4 kV/mm when 70 and 30 wt.% BNKT particles were added, which was higher than that of the single ferroelectric or relaxor phase. The starting powders were weighed according to the compositions of 2LF for the matrix and 0.5BZ for the seed phase. Ceramic powders were prepared using a conventional solid state reaction method. To prepare the composite samples, the calcined 0.5BZ–seed and 2LF–matrix powders were mixed with a mortar and pestle by varying the weight fraction (f) of the seed particles with f = 0, 0.1, 0.2, 0.3, 0.5, 0.7 and 1. |
