Effect of Sn²⁺ Ion Substitution on Dielectric Properties of (Ba,Ca)TiO₃ Ferroelectric Ceramics

Abstract

In this study, we investigated the sintering atmosphere dependence of the electric properties of Sn-doped (Ba0.82Ca0.13)TiO3 ceramics to clarify the effect of Sn2+ ions. The temperature of the dielectric constant peak for Sn-doped (Ba0.82Ca0.13)TiO3 ceramics sintered in a low P(O2) (1×10-11 MPa) atmosphere is higher than that for the sample sintered in a high P(O2) (2×10-2 MPa) atmosphere. The remanent polarization and coercive field for the Sn-doped (Ba0.82Ca0.13)TiO3 ceramics sintered at low P(O2) (1×10-11 MPa) also increased compared with those of the sample sintered at high P(O2) (2×10-2 MPa) at room temperature. The low P(O2) sintering atmosphere for Sn-doped (Ba0.82Ca0.13)TiO3 ceramics leads to a high tetragonality and the existence of Sn2+ ions. In addition, by X-ray absorption spectroscopy, it was verified that Sn2+ ions occupy Ba2+ sites in the (Ba0.82Ca0.13)TiO3 ceramics. Consequently, it is concluded that the high ferroelectric-to-paraelectric phase transition temperature and the high remanent polarization on the ceramics originate from Sn2+ ions substituted for Ba2+ sites in Sn-doped (Ba0.82Ca0.13)TiO3 ceramics.

Average and local structure of the Pb-free ferroelectric perovskites(Sr,Sn)TiO3and(Ba,Ca,Sn)Laurita1, Page2, Suzuki3 et al. 2015Phys. Rev. BSelf Cite273220View full textAdd to dashboardCite

“…8,9,[15][16][17][18] Time-of-flight (TOF) neutron scattering data were collected on powdered samples on the Nanoscale Ordered Materials Diffractometer (NOMAD) at the Spallation Neutron Source (SNS) located at Oak Ridge National Laboratory (ORNL) with a collection time between 2 h to 4 h per sample. 23 Samples were loaded in a fused silica capillary, and an empty capillary was collected and subtracted as background.…”

“…Room temperature lattice parameters are in good agreement with the literature for the nominal composition. 15,16 Isotropic ADPs of all atoms are relatively high at room temperature, suggesting there is site disorder which deviates from the welldescribed special positions of the cubic perovskite structure. High ADPs persist for Ti at 400 K, and for the axial oxygens (O1) in the TiO 6 octahedra.…”

“…These compounds have been previously characterized from the viewpoint of their dielectric properties, Raman spectroscopy, average x-ray structure, and electron microscopy. 8,9,[15][16][17][18] Some of the key findings that emerge include that despite the small substitution levels, the Sn 2+ lone pairs drive the local ordering behavior. The local structure of both compounds more closely follow the behavior of PbTiO 3 than that of the parent compounds SrTiO 3 and BaTiO 3 , respectively.…”

First-principles studies of lone-pair-induced distortions in epitaxial phases of perovskiteSnTiO3andPbTiO3

“…For example, doping (Ba,Ca)TiO 3 FE ceramics and the incipient FE SrTiO 3 with tin resulted in the enhancement [28][29][30][31] Modern epitaxial engineering techniques can stabilize metastable structures through artificial elastic boundary conditions (misfit strain) and/or rate-limited kinetics. 38 Therefore, they offer an alternative approach to avoid the restrictions imposed by bulk thermodynamics in order to grow novel materials with enhanced properties that have the potential to replace PZT in a variety of technological applications.…”

Strain Mechanisms in Lead-Free Ferroelectrics for Actuators

“…So far, chemical modifications and a controlled microstructure led to a maximum ~ 160 °C on this family of materials. [266][267][268][269] In the search for new lead-free piezoceramics, an attempt was made to look for a cation comparable to Pb 2+ . The cation Bi 3+ was discussed as a candidate due to similar ionic radii and inertpair 6s 2 electrons as in Pb 2+ .…”