Evolution from ferroelectric to diffused ferroelectric, and relaxor ferroelectric in BaTiO3-BiFeO3 solid solutions

(1−x)BaTiO3-xBiFeO3 ((1−x)BT-xBF) (x = 0-0.08) ceramics are synthesized via the conventional solid state method. And the influences of BF on the crystal structure, micromorphology and dielectric properties of BT ceramics have been investigated. X-ray diffractometer (XRD) and Raman spectra demonstrate a systematically structural transition from tetragonal to pseudo-cubic phase occurs from 0 ≤ x ≤ 0.08. The grain size of the samples becomes smaller and more uniform with the elevation of x. Dielectric behaviors display that the samples with x = 0, 0.06, and 0.08 belong to normal ferroelectric, diffused ferroelectric, and relaxor ferroelectric, respectively. High frequency independent conductivity arises for x = 0.06 and x = 0.08 due to the mobility of O2− ions and the defects generated in grain and grain boundary, which is in association with hopping of charge carriers along the Fe2+-Vo¨-Fe3+ chain and between Fe2+ and Fe3+ ions, respectively, indicate different hopping process for electrons. The polarization-electric loops become narrow, demonstrate that there are the paraelectric and cubic phase exist in the ceramics, which is in agreement with the XRD patterns and Raman spectra of the BT-BF ceramics.