Effect of Oxygen Vacancy and Oxygen Vacancy Migration on Dielectric Response of BaTiO₃-Based Ceramics

Unfolding grain size effects in barium titanate ferroelectric ceramics

“…It was suggested that this represents a possible cause of point defects in the ceramics prepared by the conventional route 52 . Point defects tend to migrate to the domain boundaries or grain boundaries and subsequently pin the domain walls 53 54 55 56 57 . In our BaTiO 3 samples, domain wall pinning effects seem to increase with increasing sintering temperature as demonstrated in Fig.…”

Unique Noncontact Monitoring of Human Respiration and Sweat Evaporation Using a CsPb2Br5-Based Sensor

“…This result is interesting because humidity sensitivity was observed to decrease with increasing frequency (Figure S7); sensitivity at 0.1 kHz was 17 287 pF/% RH, while it was dramatically lower at 0.5 and 1 kHz; i.e., 22 and 4%, respectively. Generally, there are four types of polarization mechanism (i.e., electronic polarization ( P elec ), ionic polarization ( P ion ), orientation polarization ( P or ), and interfacial polarization ( P int )) that contribute to the polarization of a dielectric material. , The total polarization of the dielectric material is calculated as the sum of all of the above contributions. P elec and P ion from the lattice are referred to as “intrinsic contributions,” whereas P or and P int are referred to as “extrinsic contributions,” and of them, P int plays the most important role in increasing dielectric permittivity.…”

Effect of atomic vacancies on ionic polarization of nonstoichiometric strontium titanate ceramics

“…Characteristics such as dielectric permittivity, piezoelectric coefficient, elastic coefficient, resistivity, remanent polarization, and coercive electric field are known to be dependent on the concentration of atomic vacancies, and therefore the precise control of defects is required to control the properties of perovskite-type oxides. [38][39][40][41][42][43][44][45][46][47][48][49][50][51][52] Regarding the influence of atomic vacancies on dielectric properties, a number of studies on the barium titanate (BaTiO 3 ) system have been conducted since the control of oxygen vacancies is one of the most important issues in the development of multilayer ceramic capacitors. 53,54) In general, the dielectric permittivity decreases with increasing concentration of atomic vacancies in BaTiO 3 , [38][39][40][41] and this phenomenon is understood as the reduction of dipole and ionic polarizations.…”

“…[38][39][40][41][42][43][44][45][46][47][48][49][50][51][52] Regarding the influence of atomic vacancies on dielectric properties, a number of studies on the barium titanate (BaTiO 3 ) system have been conducted since the control of oxygen vacancies is one of the most important issues in the development of multilayer ceramic capacitors. 53,54) In general, the dielectric permittivity decreases with increasing concentration of atomic vacancies in BaTiO 3 , [38][39][40][41] and this phenomenon is understood as the reduction of dipole and ionic polarizations. [40][41][42] The dipole polarization of BaTiO 3 mainly originates from the 90°domain-wall motion induced by the external electric field, and the reduction of dipole polarization is due to the pinning of 90°domain walls by oxygen vacancies.…”

“…53,54) In general, the dielectric permittivity decreases with increasing concentration of atomic vacancies in BaTiO 3 , [38][39][40][41] and this phenomenon is understood as the reduction of dipole and ionic polarizations. [40][41][42] The dipole polarization of BaTiO 3 mainly originates from the 90°domain-wall motion induced by the external electric field, and the reduction of dipole polarization is due to the pinning of 90°domain walls by oxygen vacancies. On the other hand, the ionic polarization is due to the ionic displacement induced by the external electric field, and it is explained by the lattice vibrations (phonons).…”