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Full-Text Articles in Nanoscience and Nanotechnology

Activation And Assembly Of Plasmonic-Magnetic Nanosurfactants For Encapsulation And Triggered Release, Fei Liu, Yifan Li, Yanhua Huang, Ayuna Tsyrenova, Kyle Miller, Lin Zhou, Hantang Qin, Shan Jiang Nov 2020

Activation And Assembly Of Plasmonic-Magnetic Nanosurfactants For Encapsulation And Triggered Release, Fei Liu, Yifan Li, Yanhua Huang, Ayuna Tsyrenova, Kyle Miller, Lin Zhou, Hantang Qin, Shan Jiang

Materials Science and Engineering Publications

Multifunctional surfactants hold great potentials in catalysis, separation, and biomedicine. Highly active plasmonic-magnetic nanosurfactants are developed through a novel acid activation treatment of Au–Fe3O4 dumbbell nanocrystals. The activation step significantly boosts nanosurfactant surface energy and enables the strong adsorption at interfaces, which reduces the interfacial energy one order of magnitude. Mediated through the adsorption at the emulsion interfaces, the nanosurfactants are further constructed into free-standing hierarchical structures, including capsules, inverse capsules, and two-dimensional sheets. The nanosurfactant orientation and assembly structures follow the same packing parameter principles of surfactant molecules. Furthermore, nanosurfactants demonstrate the capability to disperse and encapsulate homogeneous ...


Combustion Synthesis, Structural, Magnetic And Dielectric Properties Of Gd3+-Doped Lead Molybdato–Tungstates, T. Groń, M. Maciejkowicz, E. Tomaszewicz, M. Guzik, M. Oboz, B. Sawicki, S. Pawlus, A. Nowok, Z. Kukuła Oct 2020

Combustion Synthesis, Structural, Magnetic And Dielectric Properties Of Gd3+-Doped Lead Molybdato–Tungstates, T. Groń, M. Maciejkowicz, E. Tomaszewicz, M. Guzik, M. Oboz, B. Sawicki, S. Pawlus, A. Nowok, Z. Kukuła

Journal of Advanced Ceramics

Gd3+-doped lead molybdato–tungstates with the chemical formula of Pb1–3xħxGd2x(MoO4)1–3x(WO4)3x (where x = 0.0455, 0.0839, 0.1430, corresponding to 9.53, 18.32, 33.37 mol% of Gd3+, respectively, as well as ħ denotes cationic vacancies) were successfully synthesized via combustion route. The XRD and SEM results confirmed the formation of single-phase, tetragonal scheelite-type materials (space group I41/a) with the uniform, spherical and oval grains ranging from 5 to 20 μm. Individual grains are strongly agglomerated into big clusters with the ...


Ruddlesden-Popper Phase A2Bo4 Oxides: Recent Studies On Structure, Electrical, Dielectric, And Optical Properties, Gurudeo Nirala, Dharmendra Yadav, Shail Upadhyay Oct 2020

Ruddlesden-Popper Phase A2Bo4 Oxides: Recent Studies On Structure, Electrical, Dielectric, And Optical Properties, Gurudeo Nirala, Dharmendra Yadav, Shail Upadhyay

Journal of Advanced Ceramics

In the last two decades, structure and properties of Ruddlesden–Popper phase (RP) A2BO4 oxides with K2NiF4 structure, have been widely investigated. But to the best of our knowledge, no review article is available in the literature on recent studies on these oxides. Therefore, in this article, recent studies on structure, electrical, dielectric, and optical properties of these oxides have been reviewed. Special attention is put on to highlight the effect of doping and oxygen stoichiometry on the structure and properties of these oxides. Further, important applications of these oxides have also been mentioned ...


Structural, Thermomagnetic, And Dielectric Properties Of Mn0.5Zn0.5GdXFe2–XO4 (X = 0, 0.025, 0.050, 0.075, And 0.1), Lakshita Phor, Vinod Kumar Oct 2020

Structural, Thermomagnetic, And Dielectric Properties Of Mn0.5Zn0.5GdXFe2–XO4 (X = 0, 0.025, 0.050, 0.075, And 0.1), Lakshita Phor, Vinod Kumar

Journal of Advanced Ceramics

In this paper, effect of Gd3+ was investigated on structural, magnetic, and dielectric properties of Mn0.5Zn0.5GdxFe2–xO4 (x = 0, 0.025, 0.050, 0.075, and 0.1) nanoparticles prepared by facile coprecipitation method. X-ray diffraction (XRD) studies confirmed the single cubic spinel phase for all the samples and showed that lattice parameter (aexp) was found to increase from 8.414 to 8.446 Å with the substitution of Gd3+ ions due to their larger ionic radii than the replaced Fe3+ ions. Shape and size ...


Microstructure Modification Of Y2O3 Stabilized Zro2 Thermal Barrier Coatings By Laser Glazing And The Effects On The Hot Corrosion Resistance, Lei Guo, Hui Xin, Zhao Zhang, Xinmu Zhang, Fuxing Ye Oct 2020

Microstructure Modification Of Y2O3 Stabilized Zro2 Thermal Barrier Coatings By Laser Glazing And The Effects On The Hot Corrosion Resistance, Lei Guo, Hui Xin, Zhao Zhang, Xinmu Zhang, Fuxing Ye

Journal of Advanced Ceramics

Y2O3 stabilized ZrO2 (YSZ) thermal barrier coatings (TBCs) are prone to hot corrosion by molten salts. In this study, the microstructure of atmospheric plasma spraying YSZ TBCs is modified by laser glazing in order to improve the corrosion resistance. By optimizing the laser parameters, a ~18 μm smooth glazed layer with some vertical cracks was produced on the coating surfaces. The as-sprayed and modified coatings were both exposed to hot corrosion tests at 700 and 1000 ℃ for 4 h in V2O5 molten salt, and the results revealed that the modified one had improved ...


Effect Of Sintering Temperature In Argon Atmosphere On Microstructure And Properties Of 3d Printed Alumina Ceramic Cores, He Li, Yongsheng Liu, Yansong Liu, Qingfeng Zeng, Kehui Hu, Zhigang Lu, Jingjing Liang Oct 2020

Effect Of Sintering Temperature In Argon Atmosphere On Microstructure And Properties Of 3d Printed Alumina Ceramic Cores, He Li, Yongsheng Liu, Yansong Liu, Qingfeng Zeng, Kehui Hu, Zhigang Lu, Jingjing Liang

Journal of Advanced Ceramics

Alumina ceramics with different sintering temperatures in argon atmosphere were obtained using stereolithography-based 3D printing. The effects of sintering temperature on microstructure and physical and mechanical properties were investigated. The results show that the average particle size, shrinkage, bulk density, crystallite size, flexural strength, Vickers hardness, and nanoindentation hardness increased with the increase in sintering temperature, whereas the open porosity decreased with increasing sintering temperature. No change was observed in phase composition, chemical bond, atomic ratio, and surface roughness. For the sintered samples, the shrinkage in Z direction is much greater than that in X or Y direction. The optimum ...


Enhanced Dielectric And Electrocaloric Properties In Lead-Free Rod-Like Bczt Ceramics, Zouhair Hanani, Soukaina Merselmiz, Abdelaadim Danine, Nicolas Stein, Daoud Mezzane, M’Barek Amjoud, Mohammed Lahcini, Yaovi Gagou, Matjaz Spreitzer, Damjan Vengust, Zdravko Kutnjak, Mimoun El Marssi, Igor A. Luk'yanchuk, Mohamed Gouné Oct 2020

Enhanced Dielectric And Electrocaloric Properties In Lead-Free Rod-Like Bczt Ceramics, Zouhair Hanani, Soukaina Merselmiz, Abdelaadim Danine, Nicolas Stein, Daoud Mezzane, M’Barek Amjoud, Mohammed Lahcini, Yaovi Gagou, Matjaz Spreitzer, Damjan Vengust, Zdravko Kutnjak, Mimoun El Marssi, Igor A. Luk'yanchuk, Mohamed Gouné

Journal of Advanced Ceramics

Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT) lead-free ceramics demonstrated excellent dielectric, ferroelectric, and piezoelectric properties at the morphotropic phase boundary (MPB). So far, to study the effect of morphological changes on dielectric and ferroelectric properties in lead-free BCZT ceramics, researchers have mostly focused on the influence of spherical grain shape change. In this study, BCZT ceramics with rod-like grains and aspect ratio of about 10 were synthesized by surfactant-assisted solvothermal route. X-ray diffraction (XRD) and selected area electron diffraction (SAED) performed at room temperature confirm the crystallization of pure perovskite with ...


Determination Of Polarization States In (K,Na)Nbo3 Lead-Free Piezoelectric Crystal, Mao-Hua Zhang, Chengpeng Hu, Zhen Zhou, Hao Tian, Hao-Cheng Thong, Yi Xuan Liu, Xing-Yu Xu, Xiao-Qing Xi, Jing-Feng Li, Ke Wang Oct 2020

Determination Of Polarization States In (K,Na)Nbo3 Lead-Free Piezoelectric Crystal, Mao-Hua Zhang, Chengpeng Hu, Zhen Zhou, Hao Tian, Hao-Cheng Thong, Yi Xuan Liu, Xing-Yu Xu, Xiao-Qing Xi, Jing-Feng Li, Ke Wang

Journal of Advanced Ceramics

Polarization switching in lead-free (K0.40Na0.60)NbO3 (KNN) single crystals was studied by switching spectroscopy piezoresponse force microscopy (SS-PFM). Acquisition of multiple hysteresis loops on a closely spaced square grid enables polarization switching parameters to be mapped in real space. Piezoresponse amplitude and phase hysteresis loops show collective symmetric/asymmetric characteristics, affording information regarding the switching behavior of different domains. As such, the out-of-plane polarization states of the domains, including amplitudes and phases can be determined. Our results could contribute to a further understanding of the relationships between polarization switching and polarization vectors at the ...


Fabrication, Microstructure, And Properties Of Sic/Al4Sic4 Multiphase Ceramics Via An In-Situ Formed Liquid Phase Sintering, Junwen Liu, Xiaobing Zhou, Peter Tatarko, Qin Yuan, Lan Zhang, Hongjie Wang, Zhengren Huang, Qing Huang Oct 2020

Fabrication, Microstructure, And Properties Of Sic/Al4Sic4 Multiphase Ceramics Via An In-Situ Formed Liquid Phase Sintering, Junwen Liu, Xiaobing Zhou, Peter Tatarko, Qin Yuan, Lan Zhang, Hongjie Wang, Zhengren Huang, Qing Huang

Journal of Advanced Ceramics

The SiC/Al4SiC4 composites with the improved mechanical properties and thermal conductivity were fabricated by the in-situ reaction of polycarbosilane (PCS) and Al powders using spark plasma sintering. The addition of 5 wt% yttrium (Y) sintering additive was useful to obtain fully dense samples after sintering at a relatively low temperature of 1650 ℃, due to the formation of a liquid phase during sintering. The average particle size of the in-situ formed SiC was ~300 nm. The fracture toughness (4.9 MPa·m1/2), Vickers hardness (16.3 GPa), and thermal conductivity (15.8 W/(m·K ...


P–E Hysteresis Loop Going Slim In Ba0.3Sr0.7Tio3-Modified Bi0.5Na0.5Tio3 Ceramics For Energy Storage Applications, Dongxu Li, Zong-Yang Shen, Zhipeng Li, Wenqin Luo, Xingcai Wang, Zhumei Wang, Fusheng Song, Yueming Li Oct 2020

P–E Hysteresis Loop Going Slim In Ba0.3Sr0.7Tio3-Modified Bi0.5Na0.5Tio3 Ceramics For Energy Storage Applications, Dongxu Li, Zong-Yang Shen, Zhipeng Li, Wenqin Luo, Xingcai Wang, Zhumei Wang, Fusheng Song, Yueming Li

Journal of Advanced Ceramics

(Ba0.3Sr0.7)x(Bi0.5Na0.5)1-xTiO3 (BSxBNT, x = 0.3–0.8) ceramics were prepared to investigate their structure, dielectric and ferroelectric properties. BSxBNT ceramics possess pure perovskite structure accompanied from a tetragonal symmetry to pseudo-cubic one with the increase of x value, being confirmed by X-ray diffraction (XRD) and Raman results. The Tm corresponding to a temperature in the vicinity of maximum dielectric constant gradually decreases from 110 ℃ (x = 0.3) to –45 ℃ (x = 0.8), across Tm = 36 ℃ (x = 0.5) with ...


Effects Of Annealing And Firing In Wet Hydrogen On The Dielectric Breakdown Strengths Of Alumina Ceramics, Jishi Du, Binghua Tang, Wei Liu, Tao Zhang, Jiagen Peng, Hu Chen, Yangjun Lei Oct 2020

Effects Of Annealing And Firing In Wet Hydrogen On The Dielectric Breakdown Strengths Of Alumina Ceramics, Jishi Du, Binghua Tang, Wei Liu, Tao Zhang, Jiagen Peng, Hu Chen, Yangjun Lei

Journal of Advanced Ceramics

Annealing and firing in wet hydrogen are widely used steps in the processing alumina–ceramic insulators that may affect their dielectric breakdown strengths (DBS). In this study, the effects of annealing (at 1300 ℃ for 7 h) and firing in wet hydrogen on the DBS of alumina ceramics (all sintered at 1650 ℃) were studied, and the underlying mechanisms were analyzed by material characterizations. Annealing reduced the DBS of the 95% alumina ceramics due to the inter-granular phase crystallization, and the reduction in the DBS could be correlated to the reduction in mechanical strength. In contrast, annealing improved the DBS of the ...


Effects Of Calcination Temperature And Time On The Ca3Co4O9 Purity When Synthesized Using Starch-Assisted Sol–Gel Combustion Method, M. A. Mohammed, M. B. Uday, S. Izman Oct 2020

Effects Of Calcination Temperature And Time On The Ca3Co4O9 Purity When Synthesized Using Starch-Assisted Sol–Gel Combustion Method, M. A. Mohammed, M. B. Uday, S. Izman

Journal of Advanced Ceramics

Ca3Co4O9 is a p-type semiconducting material that is well-known for its thermoelectric (TE), magnetic, electronic, and electro-optic properties. In this study, sol–gel autoignition was used to prepare Ca3Co4O9 at different calcination temperatures (773, 873, 973, and 1073 K) and time (4, 6, 8, 10, 12, and 14 h) using starch as a fuel. The phase and microstructure of the prepared Ca3Co4O9 powder were investigated. Thermogravimetry–differential thermal analysis (TGA) confirms that the final weight loss occurred at 1073 K to form Ca3Co ...


Combined Quantitative Microscopy On The Microstructure And Phase Evolution In Li1.3Al0.3Ti1.7(Po4)3 Ceramics, Deniz Cihan Gunduz, Roland Schierholz, Shicheng Yu, Hermann Tempel, Hans Kungl, Rüdiger-A. Eichel Oct 2020

Combined Quantitative Microscopy On The Microstructure And Phase Evolution In Li1.3Al0.3Ti1.7(Po4)3 Ceramics, Deniz Cihan Gunduz, Roland Schierholz, Shicheng Yu, Hermann Tempel, Hans Kungl, Rüdiger-A. Eichel

Journal of Advanced Ceramics

Lithium aluminum titanium phosphate (LATP) is one of the materials under consideration as an electrolyte in future all-solid-state lithium-ion batteries. In ceramic processing, the presence of secondary phases and porosity play an important role. In a presence of more than one secondary phase and pores, image analysis must tackle the difficulties about distinguishing between these microstructural features. In this study, we study the phase evolution of LATP ceramics sintered at temperatures between 950 and 1100 ℃ by image segmentation based on energy-dispersive X-ray spectroscopy (EDS) elemental maps combined with quantitative analysis of LATP grains. We found aluminum phosphate (AlPO4) and ...


Photocatalytic Degradation Evaluation Of N–Fe Codoped Aligned Tio2 Nanorods Based On The Effect Of Annealing Temperature, Abbas Sadeghzadeh-Attar Oct 2020

Photocatalytic Degradation Evaluation Of N–Fe Codoped Aligned Tio2 Nanorods Based On The Effect Of Annealing Temperature, Abbas Sadeghzadeh-Attar

Journal of Advanced Ceramics

In this paper, a comparative study on the photocatalytic degradation of the Rhodamine B (RhB) dye as a model compound using N–Fe codoped TiO2 nanorods under UV and visible-light (λ ≥ 420 nm) irradiations has been performed. TiO2 photocatalysts were fabricated as aligned nanorod arrays by liquid-phase deposition process, annealed at different temperatures from 400 to 800 ℃. The effects of annealing temperature on the phase structure, crystallinity, BET surface area, and resulting photocatalytic activity of N–Fe codoped TiO2 nanorods were also investigated. The degradation studies confirmed that the nanorods annealed at 600 ℃ composed of both anatase ...


Mixed-Conducting Ceramic–Carbonate Membranes Exhibiting High Co2/O2 Permeation Flux And Stability At High Temperatures, R. Ortega-Lugo, J. A. Fabián-Anguiano, O. Ovalle-Encinia, C. Gómez-Yáñez, B. H. Zeifert, J. Ortiz-Landeros Oct 2020

Mixed-Conducting Ceramic–Carbonate Membranes Exhibiting High Co2/O2 Permeation Flux And Stability At High Temperatures, R. Ortega-Lugo, J. A. Fabián-Anguiano, O. Ovalle-Encinia, C. Gómez-Yáñez, B. H. Zeifert, J. Ortiz-Landeros

Journal of Advanced Ceramics

This investigation demonstrates the feasibility to fabricate high quality ceramic–carbonate membranes based on mixed-conducting ceramics. Specifically, it is reported the simultaneous CO2/O2 permeation and stability properties of membranes constituted by a combination of ceramic and carbonate phases, wherein the microstructure of the ceramic part is composed, in turn, of a mixture of fluorite and perovskite phases. These ceramics showed ionic and electronic conduction, and at the operation temperature, the carbonate phase of the membranes is in liquid state, which allows the transport of CO32– and O2– species via different mechanisms. To fabricate the ...


Highly Conductive Wear Resistant Cu/Ti3Sic2(Tic/Sic) Co-Continuous Composites Via Vacuum Infiltration Process, Dexuan Yang, Yu Zhou, Xingheng Yan, Honglei Wang, Xingui Zhou Oct 2020

Highly Conductive Wear Resistant Cu/Ti3Sic2(Tic/Sic) Co-Continuous Composites Via Vacuum Infiltration Process, Dexuan Yang, Yu Zhou, Xingheng Yan, Honglei Wang, Xingui Zhou

Journal of Advanced Ceramics

The MAX phase Ti3SiC2 has broad application prospects in the field of rail transit, nuclear protective materials and electrode materials due to its excellent electrical conductivity, self- lubricating properties and wear resistance. Cu–Ti3SiC2 co-continuous composites have superior performance due to the continuous distribution of 3D network structures. In this paper, the Cu/Ti3SiC2(TiC/SiC) co-continuous composites are formed via vacuum infiltration process from Cu and Ti3SiC2 porous ceramics. The co-continuous composites have significantly improved the flexural strength and conductivity of Ti3SiC2 due to ...


Electrical Properties And Luminescence Properties Of 0.96(K0.48Na0.52)(Nb0.95Sb0.05)–0.04bi0.5(Na0.82K0.18)0.5Zro3–Xsm Lead-Free Ceramics, Wei Li, Jigong Hao, Wei Li, Juan Du, Peng Fu, Wenzhi Sun, Chong Chen, Zhijun Xu, Ruiqing Chu Oct 2020

Electrical Properties And Luminescence Properties Of 0.96(K0.48Na0.52)(Nb0.95Sb0.05)–0.04bi0.5(Na0.82K0.18)0.5Zro3–Xsm Lead-Free Ceramics, Wei Li, Jigong Hao, Wei Li, Juan Du, Peng Fu, Wenzhi Sun, Chong Chen, Zhijun Xu, Ruiqing Chu

Journal of Advanced Ceramics

In this paper, Sm-doped 0.96(K0.48Na0.52)(Nb0.95Sb0.05)–0.04Bi0.5(Na0.82K0.18)0.5ZrO3 (abbreviated as KNSN–0.04BNKZ) lead-free piezoelectric ceramics were prepared by conventional solid-state sintering method and the effects of Sm2O3 on the phase structure, microstructure, electrical and luminescent properties of KNSN–0.04BNKZ potteries were studied. Results revealed that a single solid solution phase with pseudo-cubic perovskite structure was formed between KNSN–0.04BNKZ and Sm2O3. Existence of weak dielectric/ferroelectric properties ...


Mn–Co–Ni–O Thin Films Prepared By Sputtering With Alloy Target, Ruifeng Li, Qiuyun Fu, Xiaohua Zou, Zhiping Zheng, Wei Luo, Liang Yan Oct 2020

Mn–Co–Ni–O Thin Films Prepared By Sputtering With Alloy Target, Ruifeng Li, Qiuyun Fu, Xiaohua Zou, Zhiping Zheng, Wei Luo, Liang Yan

Journal of Advanced Ceramics

The thin film of heat-sensitive materials has been widely concerned with the current trend of miniaturization and integration of sensors. In this work, Mn1.56Co0.96Ni0.48O4 (MCNO) thin films were prepared on SiO2/Si substrates by sputtering with Mn–Co–Ni alloy target and then annealing in air at different temperatures (650–900 ℃). The X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) analysis indicated that the main crystalline phase of MCNO thin films was spinel crystal structure; the surface of the thin films was very dense and uniform. The ...


Niwo4 Powders Prepared Via Polymeric Precursor Method For Application As Ceramic Luminescent Pigments, Naiara A. Lima, Lorena D. S. Alencar, Máximo Siu-Li, Carlos A. C. Feitosa, Alexandre Mesquita, Jean-Claude M'Peko, Maria I. B. Bernardi Oct 2020

Niwo4 Powders Prepared Via Polymeric Precursor Method For Application As Ceramic Luminescent Pigments, Naiara A. Lima, Lorena D. S. Alencar, Máximo Siu-Li, Carlos A. C. Feitosa, Alexandre Mesquita, Jean-Claude M'Peko, Maria I. B. Bernardi

Journal of Advanced Ceramics

NiWO4 was prepared using the polymeric precursor method and studied in terms of physical and chemical properties to verify its stability for industrial applications as pigments. The characterization was accomplished using thermal analyses, X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) and UV–Vis spectroscopies, colorimetric coordinates, and Raman spectra. Increasing the temperature, successive exothermic reactions were observed and they are related with thermal decomposition of the organic compound. The stability was reached at ~700 ℃. The material is verified to become completely free of second phase at ~800 ℃. The end NiWO4 powders showed an intense charge transfer ...


Red-Emitting Yag:Ce,Mn Transparent Ceramics For Warm Wleds Application, Junrong Ling, Youfu Zhou, Wentao Xu, He Lin, Shuai Lu, Bin Wang, Kun Wang Oct 2020

Red-Emitting Yag:Ce,Mn Transparent Ceramics For Warm Wleds Application, Junrong Ling, Youfu Zhou, Wentao Xu, He Lin, Shuai Lu, Bin Wang, Kun Wang

Journal of Advanced Ceramics

A series of YAG:Ce,Mn transparent ceramics were prepared via a solid-state reaction-vacuum sintering method. The effects of various Mn2+–Si4+ pair doping levels on the structure, transmittance, and luminescence properties were systematically investigated. These transparent ceramics have average grain sizes of 10–16 μm, clean grain boundaries, and excellent transmittance up to 83.4% at 800 nm. Under the excitation of 460 nm, three obvious emission peaks appear at 533, 590, and 745 nm, which can be assigned to the transition 5d→4f of Ce3+ and 4T16A1 of Mn2 ...


Molten Salt Synthesis, Formation Mechanism, And Oxidation Behavior Of Nanocrystalline Hfb2 Powders, Da Liu, Qiangang Fu, Yanhui Chu Oct 2020

Molten Salt Synthesis, Formation Mechanism, And Oxidation Behavior Of Nanocrystalline Hfb2 Powders, Da Liu, Qiangang Fu, Yanhui Chu

Journal of Advanced Ceramics

Nanocrystalline HfB2 powders were successfully synthesized by molten salt synthesis technique at 1373 K using B and HfO2 as precursors within KCl/NaCl molten salts. The results showed that the as-synthesized powders exhibited an irregular polyhedral morphology with the average particle size of 155 nm and possessed a single-crystalline structure. From a fundamental aspect, we demonstrated the molten-salt assisted formation mechanism that the molten salts could accelerate the diffusion rate of the reactants and improve the chemical reaction rate of the reactants in the system to induce the synthesis of the high-purity nanocrystalline powders. Thermogravimetric analysis showed that ...


Synthesis And Characterization Of Two-Dimensional Lead-Free (K, Na)Nbo3 Micro/Nano Piezoelectric Structures, Li-Qian Cheng, Mei Feng, Yiwen Sun, Zhen Zhou, Ze Xu Oct 2020

Synthesis And Characterization Of Two-Dimensional Lead-Free (K, Na)Nbo3 Micro/Nano Piezoelectric Structures, Li-Qian Cheng, Mei Feng, Yiwen Sun, Zhen Zhou, Ze Xu

Journal of Advanced Ceramics

Two-dimensional (2D) lead-free (K, Na)NbO3 (KNN) micro/nano structures with controllable K/Na ratio were successfully fabricated via a two-step molten salt synthesis (MSS). In this work, the reaction factors, including the proportion of molten salts, the types of carbonates, the sintering temperature, and the sintering time, were discussed in detail and the optimized condition was identified. The microstructure of KNN was confirmed by confocal Raman spectroscopy, while piezoresponse force microscopy (PFM) was applied to measure three-dimensional (3D) morphology and piezoelectric properties of KNN particles. The as-synthesized KNN platelets apparently possess anisotropic morphology and uniform structure, the size ...


Nanowires-Assembled Wo3 Nanomesh For Fast Detection Of Ppb-Level No2 At Low Temperature, Di Liu, Xiaowei Ren, Yesheng Li, Zilong Tang, Zhongtai Zhang Oct 2020

Nanowires-Assembled Wo3 Nanomesh For Fast Detection Of Ppb-Level No2 At Low Temperature, Di Liu, Xiaowei Ren, Yesheng Li, Zilong Tang, Zhongtai Zhang

Journal of Advanced Ceramics

Hierarchical WO3 nanomesh, assembled from single-crystalline WO3 nanowires, is prepared via a hydrothermal method using thiourea (Tu) as the morphology-controlling agent. Formation of the hierarchical architecture comprising of WO3 nanowires takes place via Ostwald ripening mechanism with the growth orientation. The sensor based on WO3 nanomesh has good electrical conductivity and is therefore suitable as NO2 sensing material. The WO3 nanomesh sensor exhibited high response, short response and recovery time, and excellent selectivity towards ppb-level NO2 at low temperature of 160 ℃. The superior gas performance of the sensor was attributed to the high-purity ...


Mechanical And Biocompatible Properties Of Polymer-Infiltrated- Ceramic-Network Materials For Dental Restoration, Bencang Cui, Ranran Zhang, Fengbo Sun, Qian Ding, Yuanhua Lin, Lei Zhang, Cewen Nan Oct 2020

Mechanical And Biocompatible Properties Of Polymer-Infiltrated- Ceramic-Network Materials For Dental Restoration, Bencang Cui, Ranran Zhang, Fengbo Sun, Qian Ding, Yuanhua Lin, Lei Zhang, Cewen Nan

Journal of Advanced Ceramics

Dental restorative materials with high mechanical properties and biocompatible performances are promising. In this work, polymer-infiltrated-ceramic-network materials (PICNs) were fabricated via infiltrating polymerizable monomers into porous ceramic networks and incorporated with hydroxyapatite nano-powders. Our results revealed that the flexural strength can be enhanced up to 157.32 MPa, and elastic modulus and Vickers hardness can be achieved up to 19.4 and 1.31 GPa, respectively, which are comparable with the commercial computer-aided design and computer-aided manufacturing (CAD/CAM) blocks. Additionally, the adhesion and spreading of rat bone marrow mesenchymal stem cells (rBMSCs) on the surface of such materials can ...


Sol–Gel Derived Porous Ultra-High Temperature Ceramics, Fei Li, Xiao Huang, Ji-Xuan Liu, Guo-Jun Zhang Oct 2020

Sol–Gel Derived Porous Ultra-High Temperature Ceramics, Fei Li, Xiao Huang, Ji-Xuan Liu, Guo-Jun Zhang

Journal of Advanced Ceramics

Ultra-high temperature ceramics (UHTCs) are considered as a family of nonmetallic and inorganic materials that have melting point over 3000 ℃. Chemically, nearly all UHTCs are borides, carbides, and nitrides of early transition metals (e.g., Zr, Hf, Nb, Ta). Within the last two decades, except for the great achievements in the densification, microstructure tailoring, and mechanical property improvements of UHTCs, many methods have been established for the preparation of porous UHTCs, aiming to develop high-temperature resistant, sintering resistant, and lightweight materials that will withstand temperatures as high as 2000 ℃ for long periods of time. Amongst the synthesis methods for porous ...


Determination Of The Load-Independent Hardness By Analyzing The Nanoindentation Loading Curves: A Case Study On Fused Silica, Yunbiao Duan, Danyu Jiang, Jin Hu Oct 2020

Determination Of The Load-Independent Hardness By Analyzing The Nanoindentation Loading Curves: A Case Study On Fused Silica, Yunbiao Duan, Danyu Jiang, Jin Hu

Journal of Advanced Ceramics

The nanoindentation loading curves measured on fused silica were analyzed based on the theoretical relationship derived by Malzbender et al. (J Mater Res 2000, 15: 1209-1212). It was found that the ratio of the applied load to the square of the displacement, P/(h + hd)2, does not keep constant during loading segment of the nanoindentation test. Considering the existence of the indentation size effect, an empirical method for the determination of the load-independent hardness by analyzing the nanoindentation loading curves was proposed.


High-Entropy Pyrochlores With Low Thermal Conductivity For Thermal Barrier Coating Materials, Fei Li, Lin Zhou, Ji-Xuan Liu, Yongcheng Liang, Guo-Jun Zhang Oct 2020

High-Entropy Pyrochlores With Low Thermal Conductivity For Thermal Barrier Coating Materials, Fei Li, Lin Zhou, Ji-Xuan Liu, Yongcheng Liang, Guo-Jun Zhang

Journal of Advanced Ceramics

High-entropy pyrochlore-type structures based on rare-earth zirconates are successfully produced by conventional solid-state reaction method. Six rare-earth oxides (La2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, and Y2O3) and ZrO2 are used as the raw powders. Five out of the six rare-earth oxides with equimolar ratio and ZrO2 are mixed and sintered at different temperatures for investigating the reaction process. The results demonstrate that the high-entropy pyrochlores (5RE1/5)2Zr2O7 have been formed after heated at 1000 ℃. The ...


Bending Fracture Behavior Of Freestanding (Gd0.9Yb0.1)2Zr2O7 Coatings By Using Digital Image Correlation And Fem Simulation With 3d Geometrical Reconstruction, Weiguo Mao, Yujie Wang, Jun Shi, Huiyu Huang, Yuncheng Wang, Liang Lv, Haoyong Yang, Chen Zou, Cuiying Dai, Xiaolei Zhu, Daining Fang Oct 2020

Bending Fracture Behavior Of Freestanding (Gd0.9Yb0.1)2Zr2O7 Coatings By Using Digital Image Correlation And Fem Simulation With 3d Geometrical Reconstruction, Weiguo Mao, Yujie Wang, Jun Shi, Huiyu Huang, Yuncheng Wang, Liang Lv, Haoyong Yang, Chen Zou, Cuiying Dai, Xiaolei Zhu, Daining Fang

Journal of Advanced Ceramics

It is important to investigate the mechanical performances of (Gd0.9Yb0.1)2Zr2O7 (GYbZ) materials deposited on irregular substrates for improving new thermal barrier coatings. Three-point bending fracture characteristics of freestanding GYbZ coating prepared by supersonic plasma sprayed (SPS) technique were investigated with the help of digital image correlation technique. The cracking time, crack propagation path, and mechanical properties of GYbZ coating were obtained. Meanwhile, the X-ray computed tomography technique was introduced to scan the microstructure of freestanding GYbZ coatings, which are used to establish three-dimensional (3D) finite element model by using the ...


Effect Of Bnnts/Matrix Interface Tailoring On Toughness And Fracture Morphology Of Hierarchical SicF/Sic Composites, Guangxiang Zhu, Qian Feng, Jinshan Yang, Jianbao Hu, Hongda Wang, Yudong Xue, Qingliang Shan, Shaoming Dong Oct 2020

Effect Of Bnnts/Matrix Interface Tailoring On Toughness And Fracture Morphology Of Hierarchical SicF/Sic Composites, Guangxiang Zhu, Qian Feng, Jinshan Yang, Jianbao Hu, Hongda Wang, Yudong Xue, Qingliang Shan, Shaoming Dong

Journal of Advanced Ceramics

A thin BN interphase is applied on BNNTs surface to tailor the interfacial bonding between BNNTs and SiC matrix in hierarchical SiCf/SiC composites. The thickness of BN interphase ranging from 10 to 70 nm can be optimized by chemical vapor deposition after BNNTs are in situ grown on SiC fiber surface. Without BN interphase, the fracture toughness of hierarchical SiCf/SiC composites can be impaired by 13.6% due to strong interfacial bonding. As long as BN interphase with 30-45 nm thickness is applied, the interfacial bonding can be optimized and fracture toughness of hierarchical composites can ...


Pzt-Nzf/Cf Ferrite Flexible Thick Films: Structural, Dielectric, Ferroelectric, And Magnetic Characterization, J. D. Bobić, G. Ferreira Teixeira, R. Grigalaitis, S. Gyergyek, M. M. Vijatović Petrović, M. Ap. Zaghete, B. D. Stojanovic Oct 2020

Pzt-Nzf/Cf Ferrite Flexible Thick Films: Structural, Dielectric, Ferroelectric, And Magnetic Characterization, J. D. Bobić, G. Ferreira Teixeira, R. Grigalaitis, S. Gyergyek, M. M. Vijatović Petrović, M. Ap. Zaghete, B. D. Stojanovic

Journal of Advanced Ceramics

The preparation and properties of thick flexible three-phase composite films based on lead zirconium titanate (PZT) and various ferrites (nickel zinc ferrite (NZF) and cobalt ferrite (CF)) were reported in this study. Properties of three-phase composite films were compared with pure polyvinylidene fluoride (PVDF) and PZT-PVDF films. X-ray diffraction data indicated the formation of well crystallized structure of PZT and NZF/CF phases, without the presence of undesirable phases. Scanning electron micrographs showed that the ceramic particles were dispersed homogeneously in the PVDF matrix and atomic force microscopy confirmed that the size of the particles is around 30 nm. Non-saturated ...