JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Junlei Qi,Minghe Cao,Yiying Chen,Ying Fang,Wengao Pan,Hua Hao,Zhonghua Yao,Zhiyong Yu,Hanxing Liu
The effects of sintering temperature on microstructure and dielectric properties of Ce doped SrTiO 3 were investigated. The dielectric properties are strongly depend on sintering temperature, the sample sintered at 1520 °C exhibits a colossal permittivity about 7000 at 1 kHz while relative permittivity of the sample sintered at 1380 °C is 770. Further investigations demonstrate that all the samples belong to P m 3 ¯ m space group and without secondary phase. The lattice parameter decrease with the increase of sintering temperature while the mean grain size of SCT (Sr 0.985 Ce 0.01 TiO 3 ) ceramics are increased. Higher sintering temperature helps to improve the dielectric properties which can be attribute to defect clusters (e.g. oxygen vacancies , Ti 3+ /Ti 4+ etc.), however the defects are more likely to become carriers in high electric field which can increase the conductivity and leakage current. With the increase of sintering temperature, the conductivity activation energies , breakdown strength and energy storage density of the samples are decreased.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2013
·
IF 2.39
Liangliang Li,Yongfei Liu,Xiaoying Qin,Di Li,Jian Zhang,Chunjun Song,Ling Wang
Highly dense and fine-grained (Sr 1− x Gd x )TiO 3− δ ceramics ( x = 0.05–0.12) were fabricated by a sol–gel process plus spark plasma sintering, and their thermoelectric properties were investigated from ∼300 K to 1100 K. The results show that the electrical resistivity of the (Sr 1− x Gd x )TiO 3− δ ceramics decreases greatly while maintaining large absolute value of the Seebeck coefficient | S | upon Gd doping. As a result, a large power factor ( PF ) greater than 10 μW cm −1 K −2 is obtained in (Sr 0.9 Gd 0.1 )TiO 3− δ in the temperature range from 400 K to 1000 K, and peak PF reaches 16 μW cm −1 K −2 at ∼570 K. Simultaneously, the lattice thermal conductivity κ L reduces remarkably (e.g. κ L decreases from 2.7 to 2.13 W m −1 K −1 at ∼1000 K). Owing to the large PF and low κ L , a record value of figure of merit ZT = 0.37 is achieved at 1006 K for (Sr 0.9 Gd 0.1 )TiO 3− δ , indicating that appropriate combinations of fine-grained microstructure with both high densities and proper doping as well as oxygen deficiency are essential to the effective enhancement of thermoelectric performance of STO-based ceramics.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 107
·期 1
·205-213
·
IF 3.9
Shenghao Wang,Hongbo Liu,Yuanyuan Wang,Hailan Qin,Jianwei Zhao,Zhilun Lu,Zhu Mao,Dawei Wang
BiFeO 3 –SrTiO 3 (BF–ST) ceramics have been considered a novel class of lead-free dielectric materials exhibiting notable dielectric constants and remarkable thermal stability. In this work, we fabricated a series of (1 − x )BF– x ST (0.32 ≤ x ≤ 0.44) ceramics near the morphotropic phase boundary and comprehensively investigated their microstructure and electrical properties, which seeks to optimize the piezoelectric performance. As the ST content increases, a gradual reduction in the rhombohedral phase fraction is observed alongside a corresponding increase in the cubic phase fraction. Although x = 0.38, the maximum grain size of 5.66 μm is obtained, accompanied by a distinctive heterogeneous core–shell microstructure, which demonstrates a high remanent polarization of 51.2 μC/cm 2 and a maximum d 33 value of 72 pC/N. Furthermore, impedance spectroscopy analysis reveals the formation of a conductive core and a nonconductive shell within the sample. These findings highlight the potential of optimized BF–ST ceramics as promising alternatives to lead-based piezoelectric materials, offering exceptional ferroelectric and piezoelectric properties.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Jiaqi He,Li Chen,Jinming Huang,Mingwei Li,Ju Zhou,Yihua Yue,Jiao Han,Yiming Zeng
This study investigates the dielectric properties of Sr 0.985 Lu 0.01 Ti 1- x Ta x O 3 ceramics co-doped with Lu and Ta as dual-donor, which were prepared using a solid-state method and sintered in a nitrogen atmosphere. The XRD results demonstrate that the dual-donor doping of Lu and Ta at Sr and Ti sites, respectively, which will improve the dielectric properties. The optimal dielectric properties were observed when x = 0.01, which the permittivity reaching approximately 220,000 and the dielectric loss is around 0.02. Through XPS and defect chemical analysis, it has been identified that the formation of point defects including , , and Ti 3+ will be produced by sintering in N 2 -atmosphere and the dual-donor doped of Lu 3+ and Ta 5+ . These point defects aggregate into dipole clusters, such as Ti 3+ Ti 3+ , and Ti 3+ , resulting in enhanced EPDD effect and reduced dielectric loss. This work provides valuable insights into the design of advanced dielectric materials with colossal permittivity.
研究领域:
材料科学
·
电子材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 16
·21188-21196
·
IF 2.478
Sun Ying,Liu Hongbo,Liu Fangchao,Liu Gang
Recently, it is shown that the thin films of BiFeO 3 –BaTiO 3 –SrTiO 3 have ultrahigh-energy storage density. However, the energy storage properties of BiFeO 3 –BaTiO 3 –SrTiO 3 ternary bulk ceramics have not been studied. In this work, the BiFeO 3 –BaTiO 3 –SrTiO 3 ceramics have been prepared by a conventional solid-state reaction method and the dielectric and electrical energy storage properties have been studied in detail. The ceramic with the composition of 0.25BiFeO 3 –0.30BaTiO 3 –0.45SrTiO 3 is experimental evidenced to be the best with the highest dielectric permittivity in the ternary system. To suppress the dielectric loss and leakage current, 0.25BiFeO 3 –0.30BaTiO 3 –0.45SrTiO 3 has been doped with Mn. Mn-doped ceramics have the same perovskite structure but the fine grains are formed and the number of pores decreases. Mn-doping reduces dielectric loss, enlarges the thermally stable zone of the dielectric, and improves the electrical energy storage density simultaneously. 2 mol% Mn-doped 0.25BiFeO 3 –0.30BaTiO 3 –0.45SrTiO 3 has the most optimized electrical energy storage properties. The energy storage density is 1.33 J/cm 3 and the efficiency is 88.5% at 185 kV/cm. The discharge energy density is 2.7 times that of undoped 0.25BiFeO 3 –0.30BaTiO 3 –0.45SrTiO 3 and 90% stored energy can release in 120 ns.
研究领域:
材料科学
·
电介质物理学
✓ 已验证
DOI
高影响因子
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