PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2023
·Vol. 25
·期 8
·6288-6294
·
IF 3.3
Xiaotong Zhang,Dawei Jiang,Yonghao Han,Yang Gao
To reveal the pressure effects on BiOX semiconductors, we performed in-situ Raman spectroscopy and electrical transport measurements on BiOI up to 26.1 GPa and 19.2 GPa. BiOI showed good structural stability, while the electron conduction characteristics maintained dominance throughout the pressure range. The influence of grain boundary conduction disappeared at pressures above 9.2 GPa. With pressure elevation, the pressure-induced lattice fragmentation and grain refinement introduced a large number of relevant levels in the energy gap and resulted in a significant increase in the conductivity of BiOI under compression. The conductivity increased by 106 at 19.2 GPa from the initial value and maintained an increase of 102 after depressurization until ambient conditions were attained. At the same time, the space charge polarization of the crystal interface layer became weaker with pressure elevation resulting in a decrease in the relative permittivity of BiOI. The calculation results of the complex permittivity showed that the frequency of orientation polarization response decreases with pressure elevation, and the complex permittivity becomes constant in the high-frequency region. Our work proves that pressure could significantly increase the carrier concentration and mobility, thus effectively improving the conductivity of BiOX semiconductors.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Liang Shi,Xueying Wang,Rui Peng,Yongcheng Lu,Cheng Liu,Dainan Zhang,Huaiwu Zhang
A series of Mn 2+ -doped Mg 1-x Mn x Ta 2 O 6 (x = 0.02, 0.04, 0.06, 0.08, 0.10, 0.12) ceramics were synthesized by solid-state reaction method. The influence of introducing Mn–O bonds as a partial replacement for Mg–O bonds on the lattice and microwave dielectric properties was systematically investigated. XRD and Rietveld refinement confirm that Mn 2+ occupies the 2a Wyckoff position and forms a pure trirutile phase. Moreover, based on the chemical bond theory, the dielectric constant is mainly affected by the ionicity of the Ta–O bond. The lattice and dielectric properties remain relatively stable with Mn 2+ doping below 0.1, but excessive Mn 2+ doping leads to pronounced distortion of the lattice, which is not beneficial for lattice stability and microwave dielectric properties. Introducing an appropriate amount of Mn–O bonds with high bond dissociation energy facilitates MgO6 octahedron stability, which improves the thermal stability of the lattice. Accordingly, the microwave dielectric properties for 0.06 Mn 2+ -doped MgTa 2 O 6 ceramics were determined: ε r = 28, Q × f = 105,000 GHz (at 7.5 GHz), τ f = 19.5 ppm/ ° C.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Wei Yuan,Lichun Cheng,Tianrui Xia,Yucheng Chen,Qianxing Long,Qingrong Yao,Shunkang Pan,Chaohao Hu
Perovskite LaCoO 3 has unique mixed ionic electronic and structural defects, which has high research value in microwave absorption field. LaCoO 3 precursor was prepared by sol-gel method, and LaCo 1− x Fe x O 3 (Fe-LCO, x = 0, 0.05, 0.1 and 0.15) with rhombic symmetric structure was successfully synthesized at 600 °C. By refinement of X-ray diffraction (XRD) (Rietveld analysis), it was found that Fe doping makes LaCoO 3 lattice constant and cell volume increase. As a dielectric loss microwave absorbing material, the electromagnetic attenuation of LaCoO 3 is mainly due to the conduction loss, while the interface and dipole polarization are secondary reasons. It finds that Fe doping can improve the wave absorption performance of LaCoO 3 . The best absorbing performance was obtained when Fe content is x = 0.1, with the maximum reflection loss of − 38.99 dB at 10.8 GHz and the effective absorption bandwidth (RL<−10 dB) is 4.48 GHz, while the corresponding thickness was only 3 mm. In summary, LaCoO 3 has broad application prospects in X and Ku bands.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICA B-CONDENSED MATTER
·
2021
·
IF 2.436
Qilin Gong,Qingsong Huang
Recently, the moiré superlattice structure (MSS) has garnered increasing attention thanks to its extensive research potential in condensed matter physics . However, how to create MSSs on non-van der Waals crystal plates is still elusive. In the present study, we propose a new method to prepare MSSs on the MoO 2 (010) surface by soaking MoO 2 in sulfur vapour at high temperature. MoO 2 is 2D non-layered materials and is prepared by annealing MoO 3 with sulfur vapour at 500 °C. The torsional modulation between two stacked monolayers is periodic, which provides additional freedom to change the material properties . Under sulfur vapour, the surface atoms of MoO 2 first change from monoclinic to tetragonal crystals, and the interlayer covalent bonds are broken at the same time. Then, the top layer and buffer layer atoms of MoO 2 form the original MSS, and the top layer continue to rotate into different twisted angles. Our work provides some inspiration and reference to the preparation of MSSs on the surface of the other 2D non-van der Waals crystals. In addition, we further compared the wettability of MSS@MoO 2 and ordinary MoO 2 powder. The results show that the surface of MSS@MoO 2 is strongly hydrophobic (approximately 140°), while that of ordinary MoO 2 is superhydrophilic (4.3°). Our results suggest that MSSs may be a potential application to change the surface wettability of materials.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 48
·21112-21118
·
IF 3.288
Yangen Xie,Chunsheng Wang,Zhijie Yang,Huiying Wei,Jingjing Wei
Self-assembly of inorganic nanocrystals into ordered superlattices is of particular importance for their application in biomedicine and solid-state optoelectronic devices. However, dimensionality-controlled self-assembly of nanocrystals is still in its infancy. Emulsion-droplet confined self-assembly could offer a solution considering that the liquid/liquid interface and inner compartments can be respectively used as 2D and 3D templates for the assembly of nanocrystals, producing assemblies with a controlled dimensionality. CdSe nanorods with different aspect ratios were synthesized, and were applied as building blocks to uncover their assembly modes within the o/w emulsion droplets. The results reveal that by using both hydrophilic and lipophilic surfactants, hydrophobic CdSe nanorods can be locked at the liquid/liquid interface to produce a 2D supracrystalline sheet. In contrast, hydrophilic surfactants alone can result in the formation of 3D supracrystalline spherical colloids in similar conditions. Lipophilic surfactants, such as octylamine, can interact with the alkyl chains coated on the CdSe nanorods strongly, which consequently modulates the assembly mode of nanorods within the emulsion droplets. By considering the soft coatings of these supracrystalline structures with two different dimensionalities, these materials could be ideal candidates for the study of their interactions with biological soft matter.
研究领域:
材料科学
·
纳米技术
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Wei Chu,Jie Zhao,Xuzhao Ma,Fei Wang,Xiaoli Zhang,Yongcui Zhang,Zhuoqun Han,Lunan Bi,Hao Wang,Baosen Zhai,Qingxuan Zhou,Ling Li
Zirconia ceramics are renowned for their exceptional thermal stability, corrosion resistance and wear resistance, making them a key material in the fields of aerospace and military defense. This study utilized finite element simulation to design and select a lattice model with the low thermal conductivity, and its mechanical properties were experimentally verified. The results indicated that the bending strength of the lattice structure could reach 433 MPa and the heat transfer temperature at the tail was significantly reduced with a cell size of 3 mm square and a wire diameter of 1 mm. Compared to traditional solid structures, the fill rate was reduced by 25.90 %. Therefore, the lattice structure exhibits characteristics of high strength, light weight and low thermal conductivity. Furthermore, lightweight and high-heat-resistance zirconia ceramic lattice screws were successfully fabricated via using photocuring 3D printing technology, achieving the transition from theoretical simulation to component application. The research in this work provides an effective strategy for the fabrication of ceramic lattice screws with lightweight and high-heat-resistance performances and exhibit the potential application in aerospace and military defense fields.
研究领域:
材料科学
·
航空航天
·
国防科技
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Wei Jia,Jingyuan Qiao,Guangchao Shi,Lingzi Zhao,Wen Zhao,Feipeng Liu,Yiyun Fang,Jingzhi Shang,Zi-Qiang Rong
Hybrid quasi-two-dimensional (quasi-2D) perovskites have attracted great interest due to their excellent photovoltaic and light-emitting properties, which enable the rapid development of high-performance perovskite-based solar cells, light-emitting diodes, and lasers. Although many efforts have been made to improve the quality and stability of organic-inorganic perovskites, the controlled synthesis of high-quality layered perovskites remains challenging. Here, single-crystalline quasi-2D (HA) 2 (MA) n-1 Pb n I 3n+1 perovskites with layer numbers of n from 1 to 3 have been synthesized in a controllable manner, exhibiting stable lattice structures and tunable optical emission. Structurally, hexylamine (HA) with longer alkyl chains was used as an organic spacer in Ruddlesden-Popper (RP) phase perovskites to improve the chemical stability of perovskites. Various ratios of precursor materials were adopted for separating pure and large-scale quasi-2D (HA) 2 (MA) n-1 Pb n I 3n+1 perovskites, in which different layer-number perovskites with tunable band gaps were obtained with the modulated fluorescence lifetimes . Our lattice structural and fluorescence-lifetime characterizations of RP-phase perovskites provide critical information on the emerging quasi-2D perovskite-crystal systems and their fluorescence relaxation dynamics. The employed strategy to synthesize high-quality perovskites (HA) 2 (MA) n-1 Pb n I 3n+1 is technically essential to develop the rising perovskite-based photovoltaic and light-emitting applications.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-9
·
IF 4.259
Xue Ruiyang,Zhang Wang,Sun Peng,Zada Imran,Guo Cuiping,Liu Qinglei,Gu Jiajun,Su Huilan,Zhang Di
pH sensor is an important and practical device with a wide application in environmental protection field and biomedical industries. An efficient way to enhance the practicability of intelligent polymer composed pH sensor is to subtilize the three-dimensional microstructure of the materials, adding measurable features to visualize the output signal. In this work, C. rubi wing scales were combined with pH-responsive smart polymer polymethylacrylic acid (PMAA) through polymerization to achieve a colour-tunable pH sensor with nature gyroid structure. Morphology and reflection characteristics of the novel composites, named G-PMAA, are carefully investigated and compared with the original biotemplate, C. rubi wing scales. The most remarkable property of G-PMAA is a single-value corresponding relationship between pH value and the reflection peak wavelength (λ max ), with a colour distinction degree of 18 nm/pH, ensuring the accuracy and authenticity of the output. The pH sensor reported here is totally reversible, which is able to show the same results after several detection circles. Besides, G-PMAA is proved to be not influenced by the detection angle, which makes it a promising pH sensor with superb sensitivity, stability, and angle-independence.
研究领域:
材料科学
·
生物医学工程
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Jian Li,Jia Liu,Yeqing He,Xiaohan Zhang,Yanxiang Jiang,Yang Wang,Wei Sun,Yuanyuan Zhou,Walther Glaubitt,Futian Liu,Haitao Wu,Fei Wang,Ling Li
High-performance dielectric ceramics are vital for next-generation microwave devices, requiring advanced doping and composite strategies to enhance material properties. The (1- x )MgAl 2 O 4 - x Y 3 Al 5 O 12 composite ceramics were found in the MgO-Al 2 O 3 -Y 2 O 3 pseudoternary phase diagram and synthesized via solid-phase reaction. The two phases coexist to improve grain size distribution and achieve a low eutectic temperature, allowing x = 0.1–0.7 samples to gain a dense microstructure ( ρ > 96 %) when sintered at 1650–1670 °C. The semi-coherent interface, coupled with the Mg 2+ /Y 3+ cation transition zone, promotes the formation of a partial solid solution, thereby alleviating interfacial stress at the grain boundaries between MgAl 2 O 4 and Y 3 Al 5 O 12 . Notably, the 0.3MgAl 2 O 4 -0.7Y 3 Al 5 O 12 ceramic exhibits satisfying microwave dielectric properties: ε r = 10.1 ± 0.24, Q × f = 195,000 ± 12,000 GHz, and τ f = −11.9 ppm/°C. In addition to phase composition and microstructure, the enhanced performance can be attributed to the optimized crystal structure. The partial substitution of Y 3+ by Mg 2+ with a smaller radius induced the “rattling” effect and abnormal large permittivity in the [YO 8 ] site. The 27 Al NMR spectra revealed an increase in the Mg-Al inversion degree in the Mg-deficient spinel structure, resulting in the elevated total covalency of the Al-O bond. The structural changes corresponded to a decrease in intrinsic dielectric loss in Mg-Al spinel and an increase in τ f in the Y-Al garnet phase. These findings indicate the (1- x )MgAl 2 O 4 - x Y 3 Al 5 O 12 ceramics have promising applications in the field of HTCC millimeter wave communications.
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
Hengjia Zhang,Tengchao Guo,Litao Lin,Bin Quan,Xiaohui Zhu,Xiaogu Huang
High temperature material with low infrared emissivity in 3–5 μm waveband plays a crucial role in the infrared stealth capability of hot-end aircraft components. In this study, 3 mol% Ce doped ZnO ceramic powders were annealed at various temperatures to reduce their infrared emissivity. The effects of the annealing temperature on the lattice structure, microscopic morphology, and elemental valence variation in the ZnO ceramic powders were systematically investigated. Additionally, a conductivity–dielectric–lattice vibration synergy theory was proposed to provide insights about the changes in the infrared emissivity of the ZnO ceramic powders. The infrared emissivity of the sample powder gradually decreased to its lowest value (0.092 at 500 °C) as the annealing temperature increased to 1100 °C, exhibiting a U-shaped curve from room temperature to 800 °C. Furthermore, the obtained powder was used as a filler to prepare a low infrared emissivity coating, which exhibited an infrared emissivity of 0.213 in 3–5 μm waveband at 500 °C. An infrared thermographic analysis of the coating indicated that it significantly suppressed infrared radiation at 500 °C, demonstrating an excellent high temperature infrared stealth performance.
研究领域:
材料科学
·
红外隐身技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Superconductivity and Novel Magnetism
·
2024
·Vol. 37
·期 8
·1475-1485
·
IF 1.6
Fu Shuai,Tan Yiyu,Sun Xiaofan,Tang Zheng,Jiao Shulin,Cai H. L.,Zhang F. M.,Zhang A. M.,Wu X. S.
Here, equal numbers of La and Mn ions are successfully introduced simultaneously in SrRuO3. With increasing La/Mn doping, all compositions crystallize in Pnma with the lattice constant, together with the RuO 6 octahedral distortion, decreases. Ferromagnetism-to-spin glass magnetic behavior is observed at x ≥ 0.23. A metal–insulator transition (MIT) occurs at lower temperatures, resulting from the disordering of the metal mixture in the lattice. The retraction of the RuO 6 octahedron increases the overlap of the Ru t 2g –O 2p orbitals and broadens the Ru 4d bandwidth, leading to weaker electron–electron interactions, which may decrease the electronic and thermal conductivity.
研究领域:
凝聚态物理
·
材料科学
·
磁性材料
·
输运理论
·
晶体结构分析
✓ 已验证
DOI
高影响因子
Virtual and Physical Prototyping
·
2022
·
IF 10.962
Xueqin Zhang,Keqiang Zhang,Bin Zhang,Ying Li,Rujie He
Ceramic lattice structures (CLSs) are promising candidates for structural applications used in conventional and extreme environments because of their extraordinary properties. Herein, CLSs with different structural configurations, including body-centred cubic (BCC), Octet, and modified body-centred cubic (MBCC), were designed and fabricated by digital light processing (DLP)-based additive manufacturing technology to explore their quasi-static and dynamic compressive behaviours. It was demonstrated that when relative density was a constant, quasi-static compressive strength (QS), quasi-static Young’s modulus (QY), and quasi-static energy absorption (QE) of CLSs with an MBCC structural configuration were the best, Octet ranked secondly, BCC was the poorest. The same thing happened on dynamic mechanical properties of CLSs. Increasing the relative density from 20% to 40% dramatically improved the QS, QY, and QE of CLSs. Furthermore, it was revealed by experiment and simulation that the quasi-static failure mode of CLSs changed from partially fracture along a specific plane to integrally fracture at most nodes as relative density increased. Furthermore, the dynamical mechanical properties of CLSs were significantly outstanding than quasi-static mechanical properties due to the strain-rate effect. This study provides a new basis for further study on tailoring the mechanical properties of CLSs.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）