Title :
Origin of the cubic-to-hexagonal phase transition in the Ba2NiWO6-BaTiO3 system
Author :
Zhao, Fei ; Yue, Zhenxing ; Zhang, Li ; Gui, Zhilun ; Li, Longtu
Author_Institution :
Dept. of Mater. Sci. & Eng., Tsinghua Univ., Beijing, China
Abstract :
Microwave dielectric ceramics with the composition of (1-x)Ba(Ni1/2W1/2)O3-xBaTiO3 (x = 0.1-0.5) were prepared by a solid-state reaction method. A cubic-to-hexagonal phase transition occurred from x = 0.15 to 0.5, where the cubic double perovskite structure transformed into the h-BaTiO3-type hexagonal perovskite structure. In this paper, we revealed a cluster model caused by a hopping mechanism as the origin of the cubic-to-hexagonal phase transition on the basis of the low frequency dielectric property results. This model was then proved by XRD analysis, XPS analysis, and HRTEM and EDS techniques, respectively.
Keywords :
X-ray chemical analysis; X-ray diffraction; X-ray photoelectron spectra; barium compounds; ceramics; crystal structure; dielectric relaxation; microwave materials; nickel compounds; permittivity; sintering; solid-state phase transformations; transmission electron microscopy; Ba2NiWO6-BaTiO3; EDS techniques; HRTEM; XPS; XRD; cluster model; crystal structure; cubic double perovskite structure; cubic-hexagonal phase transition; dielectric constant; hexagonal perovskite structure; hopping mechanism; microwave dielectric ceramic preparation; relaxation process; solid-state reaction method; Ceramics; Dielectrics; Electrons; Ferroelectric materials; Frequency; Mechanical factors; Powders; Solid state circuits; X-ray diffraction; X-ray scattering;
Conference_Titel :
Applications of Ferroelectrics, 2009. ISAF 2009. 18th IEEE International Symposium on the
Conference_Location :
Xian
Print_ISBN :
978-1-4244-4970-5
Electronic_ISBN :
1099-4734
DOI :
10.1109/ISAF.2009.5307620
