Enhancement in hybrid improper ferroelectricity of Ca3Ti2O7 ceramics by a two-stage sintering

The novel electrical properties in quasi‐2D hybrid improper ferroelectric Sr3Sn2O7 ceramic and the structural modulation

“…A significant increase in leakage current with increasing temperature is observed. In addition, low leakage current density at RT is observed in the Sr 3 Sn 2 O 7 ceramic, which is roughly two orders of magnitude less than that of Ca 3 Ti 2 O 7 ceramics, 23,33,34 indicating that Sr 3 Sn 2 O 7 ceramic possesses exceptional insulating properties.…”

“…The J-E curves showed asymmetric characteristics on the electric field axis below 130 • C, indicating the presence of an internal bias field due to the unbalanced accumulation of charged carriers and oxygen vacancies. 23,34 Additionally, the J-E curves exhibited obvious hysteretic behavior, which can be attributed to the ferroelectric polarization switching process occurring in Sr 3 Sn 2 O 7 ceramic. Besides the ohmic conduction contribution, there exists a switching current due to polarization in the positive sweep regions from 0 to +125 kV/cm and from 0 to −125 kV/cm, which is caused by the inversion of the dipole.…”

“…The J–E curves showed asymmetric characteristics on the electric field axis below 130°C, indicating the presence of an internal bias field due to the unbalanced accumulation of charged carriers and oxygen vacancies 23,34 . Additionally, the J–E curves exhibited obvious hysteretic behavior, which can be attributed to the ferroelectric polarization switching process occurring in Sr 3 Sn 2 O 7 ceramic.…”

Effect of Al2O3 Addition on Magnetoelectric Properties of Ni0.5Zn0.5Fe2O4/Ba0.8Sr0.2TiO3 Composite Ceramics

“…Simultaneously, a mixture of BaCO 3 (99.8%), SrCO 3 (99%), and TiO 2 (99%) was ball milled and calcined at 1000°C in air for 3 h to synthesize Ba 0.8 Sr 0.2 TiO 3 (BST). 33 The NZFO and BST powders were mixed at molar ratio of 1:4. An appropriate amount of NZFO/BST powder was taken and 1 wt.%, 3 wt.%, or 5 wt.% Al 2 O 3 was added to obtain the NZFO/BST powder samples.…”

“…These results confirm the presence of the ferroelectric phase (BST) and ferromagnetic phase (NZFO) in the composite ceramics, each retaining its respective characteristics. 33 It can be seen from the XRD patterns that, as the Al 2 O 3 content was increased, the crystallinity of the ceramic grains first increased then decreased. Among the samples, NZFO/BST-3%Al 2 O 3 showed the highest crystallinity, demonstrating that addition of Al 2 O 3 was beneficial to grain growth Also, with increasing Al 2 O 3 content, all the diffraction peaks moved to high angle.…”