タングステンブロンズ型(Pb_<1-X>La_<2X/3>)_5Nb_<10>O_<30>(X=0.0〜0.50)新化合物のMPB現象

概要

論文の詳細を見る
The structural and ferroelectric properties of new compounds(Pb^<2+>_<1-X>La^<3+>_<2X/3>)_5Nb_<10>O_<30>(X=0.00-0.50)were studied with respect to La^<3+> ion substitution of Pb^<2+> ion in Pb_5Nb_<10>O_<30> having the orthorhombic tungsten bronze structure. Phase identification shows that the structure of compounds will change from orthorhombic to tetragonal symmetry along with the increase of La^<3+> amount. The co-existence of two ferroelectric phases between 0.20<X<0.30 was confirmed by XRD analysis. Result of dielectric measurement also reveals the dielectric abnormality in this narrow compositional area, i. e., a rapid change of both the Curie temperature and the dielectric constant. In addition, the hysteresis loop measurement suggests that it also has significantly improved polarization properties. This set of evidences implies that the new compounds(Pb^<2+>_<1-X>La^<3+>_<2X/3>)_5Nb_<10>O_<30> show a morphotropic phase boundary(MPB)between 0.20<X<0.30.
社団法人日本セラミックス協会の論文
2000-09-01