Aging-induced double hysteresis loops in bismuth-doped (Ba,Ca)TiO₃ ferroelectric ceramics

Abstract

Bismuth-doped (Ba 1Àx Ca x )TiO 3 ceramics (x = 0.10, Bi-BCT) were prepared by a conventional solid-state reaction technique. An abnormal double-like hysteresis polarization-electric (P-E) loop was observed at room temperature for aged Bi-BCT. Raman scattering gives critical evidence for the formation of O 2À vacancies in Bi-BCT. The change from the single P-E loops in the fresh samples to the double loops in the aged samples excludes the existence of a ferroelectric-antiferroelectric transition in Bi-BCT. A reversible domain switching mechanism resulting from a symmetry-conforming shortrange ordering of point defects gives a reasonable explanation for the naturally ageinduced double-like P-E loops in Bi-BCT.

Rapid stability of ferroelectric polarization in the Ca, Ce hybrid doped BaTiO3 ceramics

“…Yun et al . use the Raman spectrum at a high frequency peak about ~827 cm −1 to show that, when the Ca 2+ ions enter into Ti sites in BaTiO 3 and form defect dipoles, the aging phenomenon with double hysteresis loops will appear24. Similar Raman results are evidenced by Puli et al .…”

“…This band at 830~840 cm −1 was found in many inequitable doping BaTiO 3 systems such as La 3+ ions, Nd 3+ ions, Eu 3+ ions, Ce 3+ ions at Ba sites, and Ca 2+ ions at Ti sites in the previous reports242527383940. According to previous works and the ion size factor in BaTiO 3 system, this mode at about ~840 cm −1 is attributed to an internal deformation of the BO 6 octahedron caused by the charge difference of different types of ions at equivalent sites in BaTiO 3 1724252738394041. Correspondingly, the weak peak at ~840 cm −1 in BaTiO 3 doping with Ce may be attributed to Ce entering Ba sites as Ce 3+ , while it has no connection with Ce 4+ at Ti sites27.…”

“…Correspondingly, the weak peak at ~840 cm −1 in BaTiO 3 doping with Ce may be attributed to Ce entering Ba sites as Ce 3+ , while it has no connection with Ce 4+ at Ti sites27. The weak peak in BaTiO 3 doping with Ca may be attributed to partial migration of Ca 2+ from Ba to Ti sites2425. So in our study, the Raman test results indicate that Ca is successfully incorporated as Ca 2+ into Ba sites, and that Ce is successfully incorporated as Ce 4+ into Ti sites in the separate doping samples, while the Ca, Ce hybrid doped samples have different substitution sites.…”

“…Some researchers have investigated the aging behavior of the Ca doped, Ca, Mn hybrid doped or Ca, Zr hybrid doped BaTiO 3 ceramics21222425. Yun et al .…”

Abnormal polar nanoregion evolution in (Bi0.09Ba0.91)(Zn0.045Ti0.955)O3 (9BZT‐BT) ceramic

“…Most researches on relaxors have been focused on lead‐containing materials, such as Pb(Zr,Ti)O 3 , Pb(Mg 1/3 Nb 2/3 )O 3 , Pb(Zn 1/3 ,Nb 2/3 )O 3 , Pb(Zr 1/3 ,Nb 2/3 )O 3 , and their solid solutions with PbTiO 3 (PT) . Because of the toxic of lead, BaTiO 3 (BT)‐based and Bi‐containing materials have been intensively studied as promising candidates to replace lead‐based materials . Bi 3+ is an excellent candidate for the substitution of Pb 2+ in perovskite oxides due to the similar atomic size and “inert‐pair” 6s 2 electronic configuration.…”