Solid solutions of the lead-free ferroelectric oxides Bi_(0.5)Na_(0.5)TiO_(3)(BNT)and Bi_(0.5)Na_(0.5)TiO_(3)(BKT),represented as(1-x)BNT-xBKT,are studied for very close compositions in the range0≤x≤0.36 to understa...Solid solutions of the lead-free ferroelectric oxides Bi_(0.5)Na_(0.5)TiO_(3)(BNT)and Bi_(0.5)Na_(0.5)TiO_(3)(BKT),represented as(1-x)BNT-xBKT,are studied for very close compositions in the range0≤x≤0.36 to understand the correlation between the structure and the properties.Compositions are varied in steps of △x=0.02 in the range0≤x≤0.1 and0.2≤x≤0.36 and△x=0.01 in the range 0.1≤x≤0.2,to precisely locate the structural transition as well as the morphotropic phase boundary(MPB)region and the compositional region of best performance.Rietveld refinement analysis of the powder X-ray diffraction patterns showed monoclinic phase up to x=0.17 and a mixture of monoclinic and tetragonal phases for x>0.17.Similarly,the density and the dielectric constant showed linear variation up to x=0.17 and a large increase above this composition,showing maximum values in the compositional range 0.22≤x≤0.26,corresponding to the MPB region.Microstructural features also showed corresponding changes,indicating close relationship between the structure,microstructure and properties of the different compositions.展开更多
文摘Solid solutions of the lead-free ferroelectric oxides Bi_(0.5)Na_(0.5)TiO_(3)(BNT)and Bi_(0.5)Na_(0.5)TiO_(3)(BKT),represented as(1-x)BNT-xBKT,are studied for very close compositions in the range0≤x≤0.36 to understand the correlation between the structure and the properties.Compositions are varied in steps of △x=0.02 in the range0≤x≤0.1 and0.2≤x≤0.36 and△x=0.01 in the range 0.1≤x≤0.2,to precisely locate the structural transition as well as the morphotropic phase boundary(MPB)region and the compositional region of best performance.Rietveld refinement analysis of the powder X-ray diffraction patterns showed monoclinic phase up to x=0.17 and a mixture of monoclinic and tetragonal phases for x>0.17.Similarly,the density and the dielectric constant showed linear variation up to x=0.17 and a large increase above this composition,showing maximum values in the compositional range 0.22≤x≤0.26,corresponding to the MPB region.Microstructural features also showed corresponding changes,indicating close relationship between the structure,microstructure and properties of the different compositions.
