0000000000347472
AUTHOR
Š. Bagdzevičius
Dynamics of Phase Transition in 0.4NBT-0.4ST-0.2PT Solid Solution
In this paper we present dielectric spectroscopy results of NBT-(0.6-x)ST-xPT with x = 0.2 solid solution. Dielectric investigations clearly showed a relaxor—normal ferroelectric phase transition at TPT = 419 K and low temperature and low frequency dispersion similar to coexistence of dipolar glass and ferroelectric phase. The mean relaxation time above the phase transition follows Vogel—Fulcher law with following parameters: E A = 0.179 eV, τ 0 = 3.39·10−14 s, T VF = 223 K.
Chemical strain effects and changed lattice dynamic in (Sr1-1.5xBix)TiO3ceramics (x ≤ 0.15)
ABSTRACTIn this work lattice strain (induced by chemical Bi substitution on A-site) effects on the lattice dynamic of SrTiO3 ceramics were investigated by broadband dielectric spectroscopy in the very broad frequency range from 10 mHz up to 30 GHz and temperatures from 30 K to 500 K. Obtained results confirmed predicted induce of the ferroelectricity and suppression of the structural phase transition due to substitution of A-site ions – chemical straining of the lattice, both happening at the local scale but evident in macroscopic dielectric spectroscopy measurements. Calculated relaxation time distribution function broadens towards the longest relaxation times with temperature decrease and…