PTCR effect of solid solutions
based on the (1-x)BaTiO3–xNa0.5Bi0.5TiO3
system
Chem.
Met. Alloys 3
(2010) 120-125
https://doi.org/10.30970/cma3.0130
O.I.
V’yunov, T.O.
Plutenko, A.G. Belous, A.V. Bilous’ko
The structure and electrophysical properties of solid solutions based on the
(1‑x)BaTiO3–xNa0.5Bi0.5TiO3
((1‑x)BT–xNBT)
system (0 ≤ x ≤ 0.6) were studied. Bulk samples were prepared by
the solid-state reaction technique. Samples were sintered in
air and in N2 atmosphere with low concentration of H2. The phase composition and the crystal structure were examined by X‑ray powder
diffraction for samples sintered in air. X-ray
powder diffractometry (XRPD)
analysis showed that in the (1‑x)BaTiO3–xNa0.5Bi0.5TiO3
system a slightly increases,
whereas c decreases with the
substitution of Na and Bi ions for Ba ions. The permittivity was investigated in wide frequency and
temperature ranges. Impedance analyses of
samples sintered in N2/H2 atmosphere indicated that both the grain boundary and the outer layer region
contribute to the positive temperature coefficient of resistivity (PTCR) effect in (1‑x)BaTiO3–xNa0.5Bi0.5TiO3 ceramics.
Resistance of the grain bulk (1), outer layer
(2), grain boundary (3) and overall resistance (4) of (1‑x)BaTiO3-xNa0.5Bi0.5TiO3
(x = 0.09) ceramics.
Keywords
Crystal structure / PTCR effect / Heterogeneous
structure / Impedance
analysis