Improved Dielectric Properties of Low-Temperature-Sintered (Ba,Sr)TiO3-Based Ceramics by Ge Substitution
- Improved Dielectric Properties of Low-Temperature-Sintered (Ba,Sr)TiO3-Based Ceramics by Ge Substitution
- 하종윤; 윤석진; 정대용; 최지원
- Dielectric; Low temperature; Dielectric loss; BST
- Issue Date
- Japanese journal of applied physics
- VOL 49, 071505-1-071505-4
- Multilayer microwave dielectric materials with low sintering temperature are required for microwave phase shifters, filters, and true-time delay
devices. We investigated the sintering and dielectric properties of (Ba0:6Sr0:4)(Ti1-xGex)O3 (BSTG; 0:05 ≤ x ≤ 0:3) ceramics. As the Ge
concentration was increased, the lattice constant of BSTG ceramics decreased, and Ba2Ge2TiO8, which is the liquid phase at low temperature,
was formed. Ba2Ge2TiO8 liquid phase may increase the sintering density. The effect of Ge substitution is the decrease in the sintering
temperature from over 1400 to 1150 ℃ in BST system ferroelectric ceramics. With increasing Ge concentration, the dielectric constant decreased
from 2190 to 530, and the dielectric loss decreased up to 0.001 (at 1 MHz) with sintering at 1150 ℃ for 2 h. When Ge was substituted at 0.05 and
0.1 mol of Ti in the BST at 1150 ℃, the dielectric constant, dielectric loss, tunability, Curie temperature, and figure of merit were 2184 and 1529,
0.002 and 0.001, 27 and 23%, -11 and -18 ℃, and 135 and 230, respectively. These compositions show microwave dielectric properties
comparable to those of (Ba0:5Sr0:5)TiO3 ferroelectrics, which are the important materials for tunable devices such as varactors, phase shifters,
and frequency agile filters.
- Appears in Collections:
- KIST Publication > Article
- Files in This Item:
There are no files associated with this item.
- RIS (EndNote)
- XLS (Excel)
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.