• Suzuki, Shoichiro
• Higai, Shinichi
• Suzuki, Keigo
• Ando, Akira
• Honda, Atsushi
• Hasegawa, Masashi
• Niwa, Ken

Abstract

<jats:p>We discuss the doping effect of Sn<jats:sup>2+</jats:sup> on ATiO<jats:sub>3</jats:sub> perovskites by comparing with those of Pb and Ba. The solution energy of Sn into A sites of ATiO<jats:sub>3</jats:sub> perovskites shows minimum when the lattice size is almost the same as that of SrTiO<jats:sub>3</jats:sub> (STO), as determined by first-principles calculations. In dielectric measurements of these STO-based ceramics, the Sn<jats:sup>2+</jats:sup>-doped STO ceramics showed a higher peak temperature than the Pb<jats:sup>2+</jats:sup>- or Ba<jats:sup>2+</jats:sup>-doped STO ceramics at the same doping amount. In addition, the maximum polarization obtained in the Sn<jats:sup>2+</jats:sup>-doped STO ceramics was larger than that obtained in the Pb<jats:sup>2+</jats:sup>- or Ba<jats:sup>2+</jats:sup>-doped ceramics in terms of the relationship between the polarization and electric field curve measurement at room temperature. The piezoresponse was also observed in the Sn<jats:sup>2+</jats:sup>-doped STO ceramics at room temperature by piezoresponse force microscopy. We propose that these effects originate from the bond length between Sn<jats:sup>2+</jats:sup> and O<jats:sup>2-</jats:sup> which is smaller than that between Pb<jats:sup>2+</jats:sup> and O<jats:sup>2-</jats:sup>. The Sn<jats:sup>2+</jats:sup> ion prefers the off-center position at the Sr<jats:sup>2+</jats:sup> site because of the retention of the stable bond length between Sn<jats:sup>2+</jats:sup> and O<jats:sup>2-</jats:sup>. These leads to the formation of polar regions and which can assist in the generation of a larger polarization.</jats:p>

Topics

• perovskite
• impedance spectroscopy
• microscopy