Temperature and DC bias dependent dielectric properties of Sr doped BaTiO3

Multifunctional barium titanate ceramics via chemical modification tuning phase structure

“…D, ε r ‐ T curves showing T R‐O , T O‐T , and T C evolutions and phase diagram (inset) of Pb 2+ ‐doped BT ceramics 56,57 . Type II: E, Evolution of ε r ‐ T curves in typically aliovalent cation doped BT ceramics at A site 22,51,58‐62 . Type I of B‐site substitution: F and G, ε r ‐ T curves showing T R‐O , T O‐T , and T C evolutions in BT ceramics by Zr 4+ , Hf 4+ , or Sn 4+ substitution 21,54,68‐73 .…”

“…However, not much attention is paid to the Pb 2+ ‐doped BT materials on account of the lead toxicity even if a higher T C can be achieved. In addition to isovalent Ca 2+ and Pb 2+ , isovalent Sr 2+ 58‐60 and some aliovalent cations can also be introduced into A site, 22,51,61,62 whereas show negative impact on the ferroelectric phase stability and long‐range ferroelectric orders, leading to the diffusion of ferroelectric‐ferroelectric or/and ferroelectric‐paraelectric phase transitions of BT. Two types of diffused behavior can be observed in the temperature dependence of dielectric constant ( ε r ‐ T ) curves, as shown in Figure 2E.…”

“…into A site not only decrease T R‐O , T O‐T , and T C but also damage ferroelectric phase, causing the diffusion of ferroelectric‐paraelectric phase transition (Type 2, Figure 2E2). 58‐62 For B (Ti 4+ )‐site substitution, the most utilized cations are valence‐stable Zr 4+ , 21,54,67‐69 Hf 4+ , 68‐70 and Sn 4+ , 68,69,71‐73 which show similar ionic radii and same valence with Ti 4+ . As displayed in Figure 2F,G, introducing Zr 4+ , Hf 4+ or Sn 4+ to B site shifts T R‐O and T O‐T to high temperature and simultaneously decreases T C of BT ceramics, therein T R‐O moves faster than T O‐T .…”

Structural correlations in the enhancement of ferroelectric property of Sr doped BaTiO3

“…The polycrystalline samples of BSTO were prepared by conventional solid state reaction method as reported previously [38]. The room temperature x-ray diffraction (XRD) measurement is performed on powder sample using D2 Phaser Desktop Bruker x-ray diffractometer with Cu-Kα radiation.…”