Enhanced dielectric and ferroelectric characteristics in Ca-modified BaTiO3 ceramics

Abstract

Ultrahigh strain and piezoelectric behavior in relaxor based ferroelectric single crystals Journal of Applied Physics 82, 1804 (1997) Synergic modification of BaTiO 3 ceramics was investigated by Ca-substitution, and the superior dielectric and ferroelectric properties were determined together with the structure evolution. X-ray diffraction (XRD) analysis demonstrated a large solubility limit above x = 0.25 in Ba 1−x Ca x TiO 3 solid solution where the fine grain structure was observed with increasing x. Room temperature dielectric constant as high as 1655 was achieved in the present ceramics together with the significantly reduced dielectric loss of 0.013 (x = 0.20 at 100 kHz), where the Curie temperature kept almost a constant while other two transition temperatures decreased continuously with increasing x. More importantly, the remanent polarization P r and dielectric strength E b were significantly enhanced by Ca-substitution, and the best P r (11.34 μC/cm 2 ) and the highest dielectric strength E b (75 kV/cm) were acquired at x = 0.25. The present ceramics should be very desirable for the applications such as high density energy storage devices. C 2013 Author(s)

Ferroelectric, piezoelectric and electrostrictive properties of Sn4+‐modified Ba0.7Ca0.3TiO3 lead‐free electroceramics

“…The compositions x=0.05 and 0.075 show the maximum values of J max as 4.71910 À5 A/cm 2 and 3.61910 À5 A/cm 2 , respectively. 12 Further, as Sn 4+ content increases from x=0.025 to 0.1, the observed E c values are in the range, 5.77 kV/cm-4.34 kV/cm, which indicates that these ceramics are relatively easy to pole and hence it may be possible to achieve better piezoelectric and electrostrictive properties. On the other hand, the compositions with x=0.00 and 0.1 does not show any intersection of P-E and J-E plots.…”

“…dielectric constant (e r ) and dielectric loss (tan d) were measured from À100°C to 150°C, at 100 kHz shown in Figure 2. 12 The peaks correspond to T O-T and T R-O are observed below (e r ) max for x=0.05 and x=0.075 (Figure 2C-D). This revealed that the T C remains almost unchanged for x=0.00 and x=0.025, whereas the orthorhombic-tetragonal (T O-T ) and rhombohedra-orthorhombic (T R-O ) may be shifted below À100°C.…”

“…6 Recently, high-performance BT-based ceramics such as (Ba,Ca)(Ti,Zr)O 3 and (Ba,Ca)(Ti,Sn)O 3 prepared by substitution of Ca 2+ at A-site and Zr 4+ /Sn 4+ at B-site exhibits the properties comparable to the lead-based soft PZT materials. 12 Modified BT-based electroceramics, that is, a binary solid solution system composed of ferroelectric BT and nonferroelectric barium stannate (BaSnO 3 ), that is, BaTi 1Àx Sn x O 3 (BTS) has attracted considerable attention due to the presence of diffused type phase transition. This is one of the important considerations in developing the temperature stability of piezoelectric properties for various practical applications.…”

“…12 Modified BT-based electroceramics, that is, a binary solid solution system composed of ferroelectric BT and nonferroelectric barium stannate (BaSnO 3 ), that is, BaTi 1Àx Sn x O 3 (BTS) has attracted considerable attention due to the presence of diffused type phase transition. [12][13][14][15][16][17][18][19][20][21] However, there is a scarcity of detailed investigation of electrostrictive properties of BT-based lead-free electroceramics, which are correlated with the structure-property-composition having the phase coexistence of orthorhombic-tetragonal (O-T) lattice symmetry, at room temperature. [13][14][15][16][17][18][19][20][21][22] In this context, many research groups have reported the dielectric, diffused phase transition, ferroelectric, and piezoelectric properties of BCST ceramics.…”

Dielectric properties of Mn-doped BaTiO3-based ceramics synthesized by wet chemical method

“…B-site substitution often comes from metal ions (Sn 4+ ) and (Zr 4+ etc.). [6] The effects of Mn-substitution in BaTiO 3 are quite unique, and the increasing interests have been received recently. [7] However, doped MnO 2 can exhibit competitive ferroelectric with the benefit of being lead free.…”