Structure and multiferroic properties of ternary (1-x)(0.8BiFeO(3)-0.2BaTiO(3)) -xK(0.5)Na(0.5)NbO(3) (0 <= x <= 0.5) solid solutions

摘要

The ternary (1-x)(0.8BiFeO(3).0.2BaTiO(3))-xKo.sNao.sNbOs (0 <= x <= 0.5) solid solutions have been successfully synthesized by a solid-state reaction route. X-ray diffraction and Rietveld refinement studies reveal the phase transition from the rhombohedral and tetragonal phases to the single tetragonal phase with x increasing. The average grain size decreases initially and then increases as x increases, whereas the remnant magnetization shows an opposite trend and reaches the maximum value of similar to 2.09 emu/g at x = 0.3. An enhanced remnant polarization of similar to 8.6 mu C/cm(2) appears at x = 0.3 due to the structure distortion and the decrement of defects. Moreover, the remanent polarization and the relative permittivity reach the maximum value of similar to 20.14 mu C/cm(2) (10 Hz) and similar to 644 (1 kHz) at x = 0.5, respectively, and the corresponding dielectric loss decreases to the lowest value of 0.022 (1 kHz). These results indicate that the properties of ternary BFO-BTO-KNN solid solutions can be modulated by adjusting the K0.5Na0.5NbO3 content to adapt to different application needs.