JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Pengfei Wang,Xiong Huang,Jianwei Zhao,Saiwei Luan,Xinyu Fu,Bo Li,Jun Yang,Zhenxiao Fu,Xiuhua Cao,Lei Zhang,Shuhui Yu,Rong Sun
It has generally been believed that the performance of ultra-thin multilayer ceramic capacitors (MLCCs) are mainly controlled by doping elements and the contribution of synthesis approaches of BaTiO 3 (BT) powders can be neglected. However, in this study, we demonstrate that the solid-state powders exhibit a heterogeneous distribution of residual BaCO 3 (BC), TiO 2 , or Ti-rich phases, whereas hydrothermal powders are characterized by a BC surface layer, which can be characterized by nanoinfrared (AFM-IR), and the divergent approaches play an important role in the “core–shell” structure. The BC layer in hydrothermal BT contributes to Ti vacancies during sintering, increasing the “core–shell” ratio in MLCCs. This results in augmented capacitance but reduced performance at elevated temperatures. Conversely, the presence of a Ti-rich phase in solid-state powders induces Ba vacancies, leading to decreased “core–shell” ratios and dielectric constants.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xiuyun Zhang,Mingnan Shangguan,Laijun Liu,Shenfeng Long,Tingting Wei,Guisheng Zhu,Yunyun Zhao,Huarui Xu
According to the literature reports, synthesis of Ba 1- x Ca x TiO 3 (BCT) ceramics with good microstructure and satisfactory dielectric property is still a challenge. So, a facile tartaric coprecipitation method in the study is proposed to prepare BCT fine powders with homogeneous morphology, high crystallinity and tetragonality. The effect of Ca 2+ doped concentration on microstructure and dielectric property was studied. Results showed that, the characteristics of the raw BCT powders greatly affected the microstructure and site occupancy of Ca 2+ in BT ceramics, which subsequently played a crucial rule on the dielectric performance. Owing to the good properties of the raw BCT powders, the as-obtained ceramics demonstrated good microstructure with uniform grain size of ∼1 μm, defined grain boundaries and densely packed without any cracks or pores. In addition, they also demonstrated much improved dielectric properties with good ε r , low tan δ , definite increase of Tc , suggesting they are compatible in application of MLCC with high performance.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2013
·
IF 1.789
Wenwen Wang,Lixin Cao,Wei Liu,Ge Su,Wenxing Zhang
BaTiO 3 powders were successfully prepared by a novel sol–gel-hydrothermal method using tetrabutyl titanate and barium acetate as the main raw materials. The phase composition and microstructure of the powders were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results indicate that BaTiO 3 powders with well-developed crystallinity and good morphology could be synthesized at 120 °C (12 h) comparatively lower than the normal sol–gel route. The crystallinity and morphology were less affected by further increasing the reaction temperature and time. However, the KOH concentration had a great impact on the crystallinity and particles size of the powders that were all cubic phase with perovskite structure.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 13
·7950-7960
·
IF 4.036
Chuanxiang Zhang,Xiqiang Li,Lingling Ding,Chen Jin,Haijun Tao
Perovskite solar cells (PSCs) are considered to be ideal energy devices, where perovskite-type organic metal halides act as light-absorbing materials. In PSCs, the photoexcitons are extracted and separated to afford high photoelectric conversion efficiency under the action of the built-in electric field (Ebi). However, the current challenge is that a low Ebi cannot provide a sufficient driving force to separate photonic excitons, which causes the captured charges to escape from the deep energy-level defect state. Here, the ferroelectric material barium titanate (BaTiO3) was directly introduced into the perovskite precursor solution to reduce the defection density (to 8.58 × 1017 cm−3) in PSCs and promote the separation of photoexcitons. Furthermore, the addition of BaTiO3 improved the quality of the perovskite film and significantly increased the photoelectric performance after the polarization treatment. This is mainly attributed to the residual polarization electric field generated by ferroelectric polarization, which increased the Ebi of the PSCs and the width of the depletion layer and inhibited the non-radiative recombination of carriers. This work provides a possibility to design and develop optoelectronic devices with high-efficiency optoelectronic response behavior.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）