Effect of B-Ions Substitution in [(K_1/2Bi_1/2)-(Na_1/2Bi_1/2)](Ti-B)O₃ System with B=Zr, Fe_1/2Nb_1/2, Zn_1/3Nb_2/3 or Mg_1/3Nb_2/3

Abstract

Phase relationship in the [(K1/2Bi1/2)1- y (Na1/2Bi1/2) y ](Ti1- x B x )O3 system with B=Zr, Fe1/2Nb1/2, Zn1/3Nb2/3 or Mg1/3Nb2/3 has been investigated by dielectric measurement and X-ray diffractometry. All of the bi-binary systems were solid-soluble throughout the entire composition range. With increasing y and x, ferroelectric Curie point decreased and the ε-T curve became flat. Composition dependence of the transition temperature was examined by varying x or y. Phase diagrams were mostly determined at room temperature on square diagrams except for a restricted area in the vicinity of (Na1/2B1/2)ZrO3, which involved a tetragonally distorted phase and could not be accounted for. The ferroelectric tetragonal phase was confined within a narrow range of x<0.1 and the rhombohedral phase was dominant in all of the systems studied here.

Influences of phase transition and microstructure on dielectric properties of Bi0.5Na0.5Zr1-xTixO3 ceramics

“…This was influenced by the distortion of the crystal lattice because Ti 4+ occupied at the Zr 4+ site. The phase transition for the Zr/Ti ratio (0.6:0.4) found in this study was in agreement with the previous report of Yamada et al [6] who mentioned that the approximate phase transition point of the BNT-BNZ binary system was at a Zr/Ti ratio of 0.6:0.4. Quantitative data of lattice parameters obtained from the comparison between the observed and calculated reflection angles with a selected d-spacing are also given in Table 1.…”

“…For a similar system of BNT-BNZ, Yamada et al [6] predicted only that the phase-transition point of the phase diagram seemed to be approximately at a Zr/Ti ratio of 0.6:0.4. In addition, a study concerning Bi 0.5 Na 0.5 Zr 1-x Ti x O 3 [BNZT] ceramic from a Zr-rich composition has not been reported.…”

Long- and short-range structure studies of KBT-KBZ solid-solutions using synchrotron radiation

“…Our SXRD results bear this out, in agreement with previous work. 15,16 This behaviour is different to the NBT-NBZ solid-solution, where the t < 1 for the whole range and lower symmetry structures (rhombohedral, monoclinic and orthorhombic) are always observed. 14 …”

Morphotropic phase boundary, segregation effect and crystal growth in the NBT–KBT system

“…Pronin et al [7] found a pseudocubic ferroelectric phase in the interval of 0.18rxr0.4. Yamada et al [8] found that the tetragonal phase boundary extended to approximately x ¼ 0.14. Sasaki et al [9] and Li et al [10] reported that a coexistence of rhombohedral/tetragonal phases lay in the region 0.16rxr0.2 by observing the splitting of XRD peaks near 401 and 471.…”