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Kecheng Li - One of the best experts on this subject based on the ideXlab platform.
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low Temperature Sintering and microwave dielectric properties of ba3ti5nb6o28 ceramics with bacu b2o5 additions
Materials Chemistry and Physics, 2009Co-Authors: Huanfu Zhou, Kecheng LiAbstract:Abstract The effects of BaCu(B2O5) (BCB) additions on the Sintering Temperature and microwave dielectric properties of Ba3Ti5Nb6O28 ceramic have been investigated using dilatometer, X-ray diffraction, scanning electron microscopy and dielectric measurement. The pure Ba3Ti5Nb6O28 ceramic shows a High Sintering Temperature (∼1250 °C) and good microwave dielectric properties as Q × f of 11,400 GHz, ɛr of 37.0, τf of −8 ppm °C−1. It was found that the addition of BCB to Ba3Ti5Nb6O28 could lower the Sintering Temperature from 1250 to 925 °C. The reduced Sintering Temperature was attributed to the BCB liquid phase. The addition of BCB also enhanced the microwave dielectric properties to Q × f of 19,191 GHz, ɛr of 38.2, τf of 12 ppm °C−1.
Huanfu Zhou - One of the best experts on this subject based on the ideXlab platform.
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phase stability low Temperature cofiring and microwave dielectric properties of bati5o11 ceramics with bacu b2o5 addition
Journal of Materials Science: Materials in Electronics, 2013Co-Authors: Huanfu Zhou, Liang Fang, Xiaobin Liu, Xiuli ChenAbstract:The effects of BaCu(B2O5) (BCB) additions on the Sintering Temperature, microstructure and microwave dielectric properties of BaTi5O11 modified with 1.0 wt% CuO (BTC) ceramic have been investigated using X-ray diffraction, scanning electron microscopy and dielectric measurement. The BTC ceramic shows a High Sintering Temperature (~1,100 °C) and good microwave dielectric properties as Q × f = 44,530 GHz, er = 40.5, τf = 39 ppm/°C. The addition of BCB to BTC effectively reduced the Sintering Temperature from 1,100 to 925 °C. The reduced Sintering Temperature was attributed to the BCB liquid phase. The BTC ceramic doped with 4 wt% BCB has a good microwave dielectric properties with Q × f = 25,502 GHz, er = 37.4, τf = 33.1 ppm/°C. The chemical compatibility of silver electrodes and low-fired samples has also been investigated.
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low Temperature Sintering and microwave dielectric properties of ba3ti5nb6o28 ceramics with bacu b2o5 additions
Materials Chemistry and Physics, 2009Co-Authors: Huanfu Zhou, Kecheng LiAbstract:Abstract The effects of BaCu(B2O5) (BCB) additions on the Sintering Temperature and microwave dielectric properties of Ba3Ti5Nb6O28 ceramic have been investigated using dilatometer, X-ray diffraction, scanning electron microscopy and dielectric measurement. The pure Ba3Ti5Nb6O28 ceramic shows a High Sintering Temperature (∼1250 °C) and good microwave dielectric properties as Q × f of 11,400 GHz, ɛr of 37.0, τf of −8 ppm °C−1. It was found that the addition of BCB to Ba3Ti5Nb6O28 could lower the Sintering Temperature from 1250 to 925 °C. The reduced Sintering Temperature was attributed to the BCB liquid phase. The addition of BCB also enhanced the microwave dielectric properties to Q × f of 19,191 GHz, ɛr of 38.2, τf of 12 ppm °C−1.
Jin An Sam Oh - One of the best experts on this subject based on the ideXlab platform.
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composite nasicon na3zr2si2po12 solid state electrolyte with enhanced na ionic conductivity effect of liquid phase Sintering
ACS Applied Materials & Interfaces, 2019Co-Authors: Jin An Sam Oh, Linchun He, Anna Plewa, Masato Morita, Yue Zhao, Tetsuo Sakamoto, Xu Song, Wei ZhaiAbstract:: NASICON-type of solid-state electrolyte, Na3Zr2Si2PO12 (NZSP), is one of the potential solid-state electrolytes for all-solid-state Na battery and Na-air battery. However, in solid-state synthesis, High Sintering Temperature above 1200 °C and long duration are required, which led to loss of volatile materials and formation of impurities at the grain boundaries. This hampers the total ionic conductivity of NZSP to be in the range of 10-4 S cm-1. Herein, we have reduced both the Sintering Temperature and time of the NZSP electrolyte by Sintering the NZSP powders with different amounts of Na2SiO3 additive, which provides the liquid phase for the Sintering process. The addition of 5 wt % Na2SiO3 has shown the Highest total ionic conductivity of 1.45 mS cm-1 at room Temperature. A systematic study of the effect of Na2SiO3 on the microstructure and electrical properties of the NZSP electrolyte is conducted by the structural study with the help of morphological and chemical observations using X-ray diffraction (XRD), scanning electron microscopy, and using focused ion-beam-time of flight-secondary ion mass spectroscopy. The XRD results revealed that cations from Na2SiO3 diffused into the bulk change the stoichiometry of NZSP, leading to an enlarged bottleneck area and hence lowering activation energy in the bulk, which contributes to the increment of the bulk ion conductivity, as indicated by the electrochemical impedance spectroscopy result. In addition, Higher density and better microstructure contribute to improved grain boundary conductivity. More importantly, this study has achieved a Highly ionic conductive NZSP only by facile addition of Na2SiO3 into the NZSP powder prior to the Sintering stage.
Sadeq Esmaeeli - One of the best experts on this subject based on the ideXlab platform.
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investigation of the effect of al2o3 y2o3 cao ayc additives on sinterability microstructure and mechanical properties of sic matrix composites a review
International Journal of Refractory Metals & Hard Materials, 2019Co-Authors: Mahdi Khodaei, Omid Yaghobizadeh, Alireza Alipour Shahraki, Sadeq EsmaeeliAbstract:Abstract Appropriate properties of SiC ceramic such as High hardness, low density, High melting point and High elastic modulus make this material as a favorite candidate for different industrial applications. Although some disadvantages including High Sintering Temperature, low sinterability, and low fracture toughness have restricted the use of this material, previous studies showed that using Al2O3-Y2O3 additives plays an effective role in the improvement of sinterability as well as the enhancement of the properties of these composites. Moreover, the addition of CaO results in the acceleration of the formation of molten phase and the improvement of sinterability. In addition, the use of these additives cause the formation of the intermetallic phases of Al5Y3O12 (YAG) and CaY2O4 and by activating the mechanisms of crack deflection, crack bridging, phase transformation, strengthening the grain boundary and changing the fracture mode from intergranular to transgranular results in improved mechanical properties. This paper attempts to investigate the effect of using Al2O3–Y2O3–CaO (AYC) additives on sinterability, microstructure, and mechanical properties of SiC matrix composites including the composites reinforced with SiC fibers and SiC matrix nano-composites. Finally, the effect of the post-Sintering annealing process under two conditions i.e., with and without applying pressure (pressureless Sintering) on microstructure and mechanical properties has been studied.
Wei Zhai - One of the best experts on this subject based on the ideXlab platform.
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composite nasicon na3zr2si2po12 solid state electrolyte with enhanced na ionic conductivity effect of liquid phase Sintering
ACS Applied Materials & Interfaces, 2019Co-Authors: Jin An Sam Oh, Linchun He, Anna Plewa, Masato Morita, Yue Zhao, Tetsuo Sakamoto, Xu Song, Wei ZhaiAbstract:: NASICON-type of solid-state electrolyte, Na3Zr2Si2PO12 (NZSP), is one of the potential solid-state electrolytes for all-solid-state Na battery and Na-air battery. However, in solid-state synthesis, High Sintering Temperature above 1200 °C and long duration are required, which led to loss of volatile materials and formation of impurities at the grain boundaries. This hampers the total ionic conductivity of NZSP to be in the range of 10-4 S cm-1. Herein, we have reduced both the Sintering Temperature and time of the NZSP electrolyte by Sintering the NZSP powders with different amounts of Na2SiO3 additive, which provides the liquid phase for the Sintering process. The addition of 5 wt % Na2SiO3 has shown the Highest total ionic conductivity of 1.45 mS cm-1 at room Temperature. A systematic study of the effect of Na2SiO3 on the microstructure and electrical properties of the NZSP electrolyte is conducted by the structural study with the help of morphological and chemical observations using X-ray diffraction (XRD), scanning electron microscopy, and using focused ion-beam-time of flight-secondary ion mass spectroscopy. The XRD results revealed that cations from Na2SiO3 diffused into the bulk change the stoichiometry of NZSP, leading to an enlarged bottleneck area and hence lowering activation energy in the bulk, which contributes to the increment of the bulk ion conductivity, as indicated by the electrochemical impedance spectroscopy result. In addition, Higher density and better microstructure contribute to improved grain boundary conductivity. More importantly, this study has achieved a Highly ionic conductive NZSP only by facile addition of Na2SiO3 into the NZSP powder prior to the Sintering stage.