المؤلفون: Spadaro, Maria Chiara, Cao, Lu, Terry, William, Balog, Richard, Yin, Feng, Palmer, Richard E.

المساهمون: H2020 Excellent Science

المصدر: Journal of Nanoparticle Research ; volume 22, issue 6 ; ISSN 1388-0764 1572-896X

مصطلحات موضوعية: Condensed Matter Physics, General Materials Science, Modeling and Simulation, General Chemistry, Atomic and Molecular Physics, and Optics, Bioengineering

الوصف: Nanostructured gold is an intriguing system for heterogeneous catalysis at low temperature. Its activity is related to choice of support selection, particle-support interaction, and especially the particle size. Here, we investigate the possibility of controlling the size of Au clusters (nanoparticles) in the novel Matrix Assembly Cluster Source (MACS), a solvent-free nanoparticle source with potential for scale-up to the gram level. The novelty of the MACS is the idea of making clusters by sputtering a pre-condensed matrix of metal atoms embedded in a condensed non-reactive gas, e.g., Ar. This concept, introduced in 2016, has already proved deposition rates several orders of magnitude higher than conventional cluster beam routes. Such scale-up in the cluster production rate is crucial for industrial research on nanocatalysis under realistic reaction condition. Here, we report a systematic study of how Au metal loading in the matrix affects the size distribution of clusters generated. Furthermore, the obtained dependence of cluster size on deposition time provides clear confirmation of cluster formation inside the matrix by ion irradiation, rather than by aggregation of atoms on the TEM support after deposition.

الإتاحة: https://doi.org/10.1007/s11051-020-04869-9Test

المؤلفون: Liu, Yu, Wang, Fangfang, Liu, Yawen, Cao, Lu, Hu, Haiming, Yao, Xiaowei, Zheng, Junping, Liu, Hongtao

المساهمون: Hubei Provincial Department of Education

المصدر: Sensors and Actuators B: Chemical ; volume 389, page 133893 ; ISSN 0925-4005

مصطلحات موضوعية: Materials Chemistry, Electrical and Electronic Engineering, Metals and Alloys, Surfaces, Coatings and Films, Condensed Matter Physics, Instrumentation, Electronic, Optical and Magnetic Materials

الإتاحة: https://doi.org/10.1016/j.snb.2023.133893Test
https://api.elsevier.com/content/article/PII:S0925400523006081?httpAccept=text/xmlTest
https://api.elsevier.com/content/article/PII:S0925400523006081?httpAccept=text/plainTest

المؤلفون: Cao Lu, Ye Wuyou, Liu Qing, Fan Tiantang, Zhang Qin, Li Jiafeng, Fan Zhong-yong, Gong Li

المصدر: CrystEngComm. 22:728-739

مصطلحات موضوعية: Pyromellitic dianhydride, Materials science, Nucleation, General Chemistry, Condensed Matter Physics, Branching (polymer chemistry), law.invention, Gel permeation chromatography, Crystallinity, chemistry.chemical_compound, Differential scanning calorimetry, stomatognathic system, chemistry, Chemical engineering, law, Volume fraction, General Materials Science, Crystallization

الوصف: A series of adjustable long chain branching poly(L-lactide)s (b-PLAs) was prepared by reactive processing of linear PLA using pyromellitic dianhydride (PMDA) and polyfunctional epoxy ether (PFE) as the branching agent and their vascular stents were fabricated via 3D-printing. Fourier-transform infrared (FTIR) spectroscopy and gel permeation chromatography (GPC) results indicated that the chain branching reaction occurs and the average molecular weight increases obviously after the chain branching reaction. Rheological tests on the b-PLAs demonstrated that they are composed of a symmetric- or asymmetric-star, or tree-like chain configuration. The volume fraction of the branching structure of the chains increased from 0.03 to 0.3 with increasing branching agent content. The effects of the branching structure on the melt crystallization behavior of b-PLAs were investigated by means of differential scanning calorimetry (DSC). The isothermal crystallization results showed that the half-time of crystallization (t1/2) of the samples decreased from 16.8 min for linear PLA to 2.3 min when the branching agent content was 2 wt% at 106 °C. Also, as observed from polarized optical microscopy experiments, the nucleation density of the b-PLAs significantly increased with increasing volume fraction of the branching structure because the enrichment of segments around the branching structure facilitated nucleation, thus the b-PLA samples have a higher probability to form a primary nucleus than linear PLA. Moreover, mechanical testing demonstrated that forming the branching structure enabled the effective modification of the mechanical properties of PLA. The microstructures with a smaller spherulite size and higher crystallinity of the b-PLAs improved their tensile strength and modulus from 45.7 MPa and 1.63 GPa to 77.2 MPa and 3.41 GPa, respectively. Furthermore, the radial force performance of the 3D printed b-PLA vascular stents was enhanced from 4.8 to 13.7 N by the branching structure of the chains. The CCK-8 assay results indicated that the osteoblast activity of b-PLA is higher than that of linear PLA, and the scanning electron microscopy (SEM) results also indicated that b-PLA was covered and flattened with a better attachment morphology for the osteoblasts than PLA. Therefore, the b-PLAs with a long chain branching structure could effectively facilitate cell growth, proliferation, and differentiation.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::4ade7bdd3270cf8e561dbc334c560ae4Test
https://doi.org/10.1039/c9ce01477bTest

المؤلفون: Hongjun Zhang, Dechang Jia, Yu Zhou, Fangzhe Li, Hua Ke, Cao Lu, Huijiadai Luo, Liwei Zhang

المصدر: Physica B: Condensed Matter. 567:17-24

مصطلحات موضوعية: 010302 applied physics, Materials science, Doping, Analytical chemistry, Ionic bonding, 02 engineering and technology, Dielectric, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Ferroelectricity, Electronic, Optical and Magnetic Materials, Tetragonal crystal system, visual_art, Phase (matter), 0103 physical sciences, visual_art.visual_art_medium, Ceramic, Electrical and Electronic Engineering, 0210 nano-technology, Sol-gel

الوصف: Lead-free ferroelectric Na0.5Bi0.5TiO3 (NBT), 0.94Na0.5Bi0.5TiO3-0.06BaTiO3 (NBT-6BT) and (Na0.5Bi0.5)0.94Ba0.06(Nb0.05Ti0.95)O3 (Nb-NBBT6) ceramics were synthesized via a multi-ionic sol-gel method process. The effects of Nb on the structural, dielectric and ferroelectric properties were studied. Doped Nb ions distributed uniformly in the Nb-NBBT6 ceramics and shrank the grain sizes of Nb-NBBT6. All NBT, NBT-6BT and Nb-NBBT6 ceramics consisted of the rhombohedral phase and the tetragonal phase according to XRD Rietveld refinements. The dielectric constants of the Nb-NBBT6 ceramics were improved compared to NBT and NBT-6BT below 200 °C. The introduction of Nb ions enhanced the dielectric stability, and the temperature difference between two dielectric peaks increased from 153 °C for NBT to 197 °C for Nb-NBBT6. The remnant polarization (Pr) of Nb-NBBT6 ceramics decreased, but the reduced Ec of 7.01 kV/cm and the maximum polarization of 40.79 μC/cm2 (90 kV/cm) revealed the enhanced ferroelectric property. The temperature-dependent ferroelectric hysteresis loops of Nb-NBBT6 ceramics (65–150 °C) exhibited the largest energy-storage density (W) of 0.399 J/cm3 at 90 °C.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::46b14ea33d3eefa2a34d2560ca0af190Test
https://doi.org/10.1016/j.physb.2019.05.008Test

المؤلفون: Cao, Lu, Song, Yang, Liu, Ya-Bin, Zheng, Qi, Han, Guangyuan, Liu, Wenyao, Li, Meng, Chen, Hui, Xing, Yuqing, Cao, Guang-Han, Ding, Hong, Lin, Xiao, Du, Shixuan, Zhang, Yu-Yang, Li, Geng, Wang, Ziqiang, Gao, Hong-Jun

المصدر: Nano Research ; volume 14, issue 11, page 3921-3925 ; ISSN 1998-0124 1998-0000

مصطلحات موضوعية: Electrical and Electronic Engineering, General Materials Science, Condensed Matter Physics, Atomic and Molecular Physics, and Optics

الإتاحة: https://doi.org/10.1007/s12274-021-3316-0Test

المؤلفون: Fangzhe Li, Yu Zhou, Cao Lu, Pengkang Guo, Liwei Zhang, Huijiadai Luo, Hongjun Zhang, Dechang Jia, Hua Ke

المصدر: Philosophical Magazine. 99:2661-2680

مصطلحات موضوعية: 010302 applied physics, Materials science, Condensed matter physics, Ferroelectric ceramics, 0103 physical sciences, 02 engineering and technology, 021001 nanoscience & nanotechnology, 0210 nano-technology, Condensed Matter Physics, 01 natural sciences, Relaxor ferroelectric

الوصف: The existence of Bi-fluctuation dispersing in Na0.5Bi0.5TiO3 (NBT) relaxor ferroelectric is hinted in other recent studies. However, this fluctuation has not been directly observed yet. We introduc...

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::78da79765487a31186d279df079d943dTest
https://doi.org/10.1080/14786435.2019.1637550Test

المؤلفون: Dechang Jia, Huijiadai Luo, Fangzhe Li, Hua Ke, Liwei Zhang, Cao Lu, Wen Wang, Yu Zhou, Hongjun Zhang, Fuli Wang

المصدر: Scripta Materialia. 164:6-11

مصطلحات موضوعية: 010302 applied physics, Diffraction, Permittivity, Phase boundary, Materials science, Magnetic domain, Condensed matter physics, Mechanical Engineering, Metals and Alloys, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, 01 natural sciences, Ferroelectricity, symbols.namesake, Mechanics of Materials, 0103 physical sciences, symbols, General Materials Science, Orthorhombic crystal system, 0210 nano-technology, Raman spectroscopy

الوصف: Morphotropic phase boundaries (MPB) consisting of rhombohedral, nonpolar orthorhombic and orthorhombic bridging phases were formed within the range of 0.1 ≤ x ≤ 0.2 in Bi1-xNdxFe0.97Ti0.03O3 ceramics. The intricate phase coexistence was verified by X-ray diffraction refinements, new modes at ~305 cm−1 in Raman spectra and microstructure analyses. Impedance tests confirmed the MPB ranges via resistance fluctuations and revealed additional arcs from phase boundaries. Ferroelectric and magnetic properties were synchronously improved at MPB resulting in the apparent magnetodielectric effect with a permittivity change rate of ~1.5% at 10000 Oe. Additionally, magnetic domains were reversed at low voltages.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::e2e525c6f884c9ce840205e79589b7a1Test
https://doi.org/10.1016/j.scriptamat.2019.01.025Test

المؤلفون: Liwei Zhang, Yu Zhou, Li Xiening, Hua Ke, Huijiadai Luo, Dechang Jia, Wen Wang, Hongjun Zhang, Jinggeng Zhao, Cao Lu, Fangzhe Li, Gang Zeng

المصدر: Scripta Materialia. 158:71-76

مصطلحات موضوعية: 010302 applied physics, Permittivity, Phase boundary, Phase transition, Materials science, Condensed matter physics, Mechanical Engineering, Metals and Alloys, 02 engineering and technology, Dielectric, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Dielectric spectroscopy, symbols.namesake, Mechanics of Materials, 0103 physical sciences, symbols, General Materials Science, Orthorhombic crystal system, 0210 nano-technology, Raman spectroscopy, Néel temperature

الوصف: Morphotropic phase boundaries (MPB) consisting of rhombohedral and orthorhombic phases formed within the range of 0.1 ≤ x ≤ 0.15 in Bi1-xErxFe0.97Ti0.03O3 ceramics. Orthorhombic phase transition was verified by the appearance of a new mode at 310 cm−1 in Raman spectra. Bridging phases as intermedia phases of MPB were rare in Bi1-xErxFe0.97Ti0.03O3. Polarization and permittivity improved at MPB. Moreover, impedance spectroscopy revealed additional arcs with a distinct small polaron conduction mechanism. Er3+ ions enhanced magnetic properties and induced a permittivity change at Neel temperature. The magnetodielectric effect resulted in a permittivity change rate of ~1% at 10000 Oe.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::a3ffd119f09c35b2f22d45e989982522Test
https://doi.org/10.1016/j.scriptamat.2018.08.030Test

المؤلفون: Liwei Zhang, Yu Zhou, Dechang Jia, Hongjun Zhang, Hua Ke, Huijiadai Luo, Fangzhe Li, Cao Lu

المصدر: Ceramics International. 44:22549-22555

مصطلحات موضوعية: 010302 applied physics, Permittivity, Materials science, Condensed matter physics, Process Chemistry and Technology, Composite number, Magnetoelectric effect, 02 engineering and technology, 021001 nanoscience & nanotechnology, Microstructure, 01 natural sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Magnetic field, visual_art, 0103 physical sciences, Materials Chemistry, Ceramics and Composites, visual_art.visual_art_medium, Grain boundary, Ceramic, 0210 nano-technology, Polarization (electrochemistry)

الوصف: Lead-free 0.9Na0.5Bi0.5TiO3 − 0.1CoFe2O4 (0.9NBT-0.1CFO) composite ceramics with novel embedded microstructures were synthesized by an in-situ sol-gel method. The structural evolution, ferroelectricities and dielectricities were studied. The embedded structures were formed around 1000 °C − 1100 °C with contributions of the strong grain boundary mobility and small size of CFO grains, and then were destroyed at 1150 °C. The 0.9NBT-0.1CFO ceramic sintered at 1100 °C showed the optimal ferroelectric hysteresis loop with a remanent polarization of ~ 52 μC/cm2. Anomaly peaks in the temperature dependent permittivity curves were observed in all ceramics with embedded structures. These Debye-like type peaks generated by the interface effects of NBT and CFO appeared around ~620 °C, and could reach relatively large values of ~15000 at 100 kHz. The change rate of permittivity between zero magnetic field and 500 Oe reached 2.4%, indicating a noteworthy magnetoelectric effect.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::39d5c112e6de06de62b1692485690338Test
https://doi.org/10.1016/j.ceramint.2018.09.027Test

المؤلفون: Fangzhe Li, Dong Li, Guangtong Liu, Xiaoli Dong, Cao Lu, Dechang Jia, Huijiadai Luo, Hua Ke, Liwei Zhang, Yu Zhou, Hongjun Zhang

المصدر: Materials Today Physics. 21:100559

مصطلحات موضوعية: Phase transition, Phase boundary, Materials science, Physics and Astronomy (miscellaneous), Condensed matter physics, Relaxation (NMR), Ferroelectricity, visual_art, Electric field, Phase (matter), visual_art.visual_art_medium, Antiferromagnetism, General Materials Science, Ceramic, Energy (miscellaneous)

الوصف: A series of experimental and theoretical studies have demonstrated that Bi1-xNdxFeO3 ceramics with morphotropic phase boundaries (MPBs) exhibit a very complex phase-transition process including the displacive ferroelectric phase transition and reorientation of antiferromagnetic alignments [Chem. Mater. 23, 2166 (2011); Adv. Funct. Mater. 25, 552 (2015)]. In this work, such complex phase-transition process in the Bi0.85Nd0.15FeO3 ceramic is detected by electric and magnetic responses as the function of frequency. First, the phase transition from orthorhombic Pbam phase (O2) to orthorhombic Pbnm phase (O1) is found to be accompanied by the change in the local strain induced by MPBs. Second, the electric response at O2→O1 transition with the disappearance of antiferroelectric order showed the relaxation and reversible rotation of the ferroelectric order coupled with the local strain. The moderate active energy of such coupling (∼2.7 eV) facilitates the possibility of recovering the deformation of Bi1-xNdxFeO3 ceramic by an external electric field. Third, the weak magnetic response is frequency-independent, and the reorientation of the antiferromagnetic order is also reversible. Finally, the rotation of ferroelectric/magnetic order connected to MPBs in the ceramic is discussed.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::9bda610212c14657efebcb160267a803Test
https://doi.org/10.1016/j.mtphys.2021.100559Test