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Hole density dependent magnetic structure and anisotropy in Fe-pnictide superconductor

Chinese physics B 2023年第9期32卷 463-467页

作者：岳远放黄忠兵黎欢明星郑晓军 College of Science Guilin University of TechnologyGuilin 541004China Key Laboratory of Low-dimensional Structural Physics and Application Education Department of Guangxi Zhuang Autonomous RegionGuilin 541004China Faculty of Physics Hubei UniversityWuhan 430062China

The competition between different magnetic structures in hole-doped Fe-pnicitides is explored based on an extended five-orbital Hubbard model including long-range Coulomb *** results show that the stabilized magnetic structure evolves with increasing hole doping ***,the stripe antiferromagnetic phase dominates at zero doping,while magnetic structures with more antiferromagnetic linking numbers such as the staggered tetramer,staggered trimer,and staggered dimer phases become energetically favorable as the hole density *** a certain doping level,energy degeneracy of different magnetic structures appears,indicating strong magnetic frustration and magnetic fluctuations in the *** suggest that the magnetic competition induced by the hole doping may explain the fast decrease of the Neel temperature TNand the moderately suppressed magnetic moment in the hole doped ***,our results show a sign reversal of the kinetic energy anisotropy as the magnetic ground state evolves,which may be the mechanism behind the puzzling sign reversal of the in-plane resistivity anisotropy in hole-doped Fe-pnicitides.

关键词： iron-pnictide superconductors magnetic structure resistivity anisotropy

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Broadband third-order optical nonlinearities of layered franckeite towards mid-infrared regime

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Chinese physics B 2024年第10期33卷 275-281页

作者： Zhi-Qiang Xu Tian-Tian Zhou Jie Li Dong-Yang Liu Yuan He Ning Li Xiao Liu Li-Li Miao Chu-Jun Zhao Shuang-Chun Wen Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education&Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices School of Physics and ElectronicsHunan UniversityChangsha 410082China School of Mechanical and Electrical Engineering Heze UniversityHeze 274015China

The study of nonlinear optical responses in the mid-infrared(mid-IR)regime is essential for advancing ultrafast mid-IR laser ***,nonlinear optical effects under mid-IR excitation are rarely reported due to the lack of suitable nonlinear optical *** natural van derWaals heterostructure franckeite,known for its narrow bandgap and stability in air,shows great potential for developing mid-IR nonlinear optical *** have experimentally demonstrated that layered franckeite exhibits a broadband wavelength-dependent nonlinear optical response in the mid-IR spectral *** nanosheets were prepared using a liquid-phase exfoliation method,and their nonlinear optical response was characterized in the spectral range of 3000 nm to 5000 *** franckeite nanosheets exhibit broadband wavelengthdependent third-order nonlinearities,with nonlinear absorption and refraction coefficients estimated to be about 10^(-7)cm/W and 10^(-11)cm^(2)/W,***,a passively Q-switched fluoride fiber laser operating around a wavelength of 2800 nm was achieved,delivering nanosecond pulses with a signal-to-noise ratio of 43.6 dB,based on the nonlinear response of *** findings indicate that layered franckeite possesses broadband nonlinear optical characteristics in the mid-IR region,potentially enabling new possibilities for mid-IR photonic devices.

关键词： third-order optical nonlinearities franckeite mid-infrared Q-switching

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Simultaneous enhancement of thermoelectric and mechanical performance in Ag2Se via Sb2Te3 compositing

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Ceramics International 2025年第13期51卷 17623-17629页

作者： Zhang, Mengqing Yang, Mengxiang Zhu, Hongyu Li, Shan Liu, Qingshan Yang, Xiaobing Su, Taichao College of Physics and Electronic Information Engineering & Key Laboratory of Low-dimensional Structural Physics and Application Education Department of Guangxi Zhuang Autonomous Region Guilin University of Technology Guilin541004 China School of Life Sciences Huzhou University Huzhou313000 China Fujian Provincial Key Laboratory of Eco-Industrial Green Technology Wuyi University Wuyishan354300 China

Silver Selenide (Ag2Se) has been deemed as an excellent candidate for substitution of the n-type Bi2Te3 for thermoelectric applications. However, the naturally high electron concentration resulting from interstitial cation and inferior mechanical performance of pristine Ag2Se significantly limit its practical application. Additionally, the conventional synthesis of Ag2Se commonly requires complex and time-consuming high temperatures melting or ball milling processes. In this study, Ag2Se composited with Sb2Te3 was synthesized through a simple manual mixing followed by a hot press sintering method. By introducing microparticle Sb2Te3, the carrier concentration of Ag2Se was suppressed and thus the Seebeck coefficient and Hall mobility were enhanced simultaneously. Furthermore, the presence of particulate Sb2Te3 and the interfaces formed between Ag2Se and Sb2Te3 intensified phonon scattering and impeded crack propagation. These lead to a suppression in thermal conductivity accompanied by an improvement in hardness. Consequently, an enhanced zT of 0.92 and an improved hardness of 71 Kgf·mm−2 were achieved for Ag2Se composited with 2 mol% and 3mol% Sb2Te3, which were approximately 30 % and 18 % higher than those of the pristine Ag2Se, respectively. These results indicate that combining manual mixing with the introduction of secondary-phase particles provides a facile approach to simultaneously optimize both the thermoelectric and mechanical performance of Ag2Se. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Brinell Hardness

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Structure evolution andτ_(f)influence mechanism of Bi_(1-x)Ho_(x)VO_(4)microwave dielectric ceramics for LTCC applications

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Journal of Materials Science & Technology 2024年第30期197卷 1-8页

作者： Huaicheng Xiang Yuheng Zhang Junqi Chen Yang Zhou Ying Tang Jinwu Chen Liang Fang Key Laboratory of Low-Dimensional Structural Physics and Application Education Department of Guangxi Zhuang Autonomous RegionCollege of Physics and Electronic Information EngineeringGuilin University of TechnologyGuilin541004China Guangxi Universities Key Laboratory of Non-Ferrous Metal Oxide Electronic Functional Materials and Devices Guangxi Key Laboratory of Optical and Electronic Materials and DevicesCollege of Materials Science and EngineeringGuilin University of TechnologyGuilin541004China School of Mechanical Engineering Guilin University of Aerospace TechnologyGuilin541004China

Bi_(1-x)Ho_(x)VO_(4)(0.1≤x≤0.9)ceramics were prepared via a solid-state reaction method,and all the ceram-ics could be well densified in the 920–980℃*** ceramics with 0.1≤x<0.4 were composed of both monoclinic scheelite(M)and tetragonal zircon(T)phases,and a single M phase could be obtained in the range of x≥*** measuredε_(r) decreased from 58.9(x=0.1)to 14.7(x=0.9),so do the calcu-lated values(ε_(r)(C−M)=34.3–12.1),and the main reason forε_(r)>ε_(r)(C−M)was the rattling of Ho^(3+)in the *** points with zeroτf appeared in Bi1–x Hox VO4(0≤x≤1)ceramics,and the best mi-crowave dielectric properties withε_(r)=16.6,Q×f=18,400 GHz(f=10.69 GHz),andτf=+3.29 ppm/℃were obtained in the Bi_(0.2)Ho_(0.8)VO_(4)*** change in temperature coefficient of ionic polarizability(τ_(αm))caused by the rattling effect of cations is the physical essence that affectsτ***,the rattling effect can be used as an effective mechanism to regulateτf in low-ε_(r) ***,there was no chemical reaction between Bi_(1-x)Ho_(x)VO_(4) and Ag electrode,which indicates potential applications in low-temperature co-fired ceramic(LTCC)technology.

关键词： Bi_(1–x)Ho_(x)VO_(4) Near-zeroτ_(f) Bond valence Rattling effect LTCC

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Competitive assembling strategy to construct carbon nitride homojunctions for boosting photocatalytic performance

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Journal of Materials Science & Technology 2024年第5期172卷 23-32页

作者： Hua-Wei Zhang Yuan-Yuan Li Bo Li Jing-Hui Shi Tao Huang Gui-Fang Huang Anlian Pan Wangyu Hu Wei-Qing Huang School of Physics&Electronic Engineering Zhengzhou University of Light IndustryZhengzhou 450002China Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education&Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices School of Physics and ElectronicsHunan UniversityChangsha 410082China College of Materials Science and Engineering Hunan UniversityChangsha 410082China

Both morphology and composition have a great influence on the properties and functions of materials,however,how to rational modulate both of them to achieve their synergistic effects has been a longstanding ***,we demonstrate a competitive assembling strategy for the construction of metal-free graphite carbon nitride(CN)homojunctions in which morphology and composition can be easily controlled simultaneously by only changing the ratio of assembly raw *** homojunctions are comprised of porous nanotubular S-doped CN(SCN)grafted with CN nanovesicles,which are derived from thermal polycondensation of melamine-thiocyanuric acid(M-T)/melamine-cyanuric acid(M-C)supramolecular hybrid *** unique architecture and component engineering endows the novel SCN-CN homojunction with abundant active sites,enhanced visible trapping ability,and intimate interface *** a result,the synthesized SCN-CN homojunctions demonstrate high photocatalytic activity for hydrogen evolution and pollutant *** developed strategy opens up intriguing opportu-nities for the rational construction of intricate metal-free heterostructures with controllable architecture and interfacial contact for applications in energy-related fields.

关键词： Competitive assembling strategy Supramolecular hybrid blocks Homojunctions Graphite carbon nitride Photocatalytic

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Cucurbituril-regulated face-to-face dimerization assembly enhanced photosensitization and photocatalysis

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Science China Chemistry 2024年第5期67卷 1605-1612页

作者： Haigen Nie Die Hu Zhiyao Zeng Yan Fan Yaxin Zhai Xin-Long Ni Key Laboratory of Chemical Biology and Traditional Chinese Medicine Ministry of Educational of ChinaKey Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan ProvinceCollege of Chemistry and Chemical EngineeringHunan Normal UniversityChangsha 410081China Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of PhysicsHunan Normal UniversityChangsha 410081China

In water, N,N′-diarylpyridinium thiazolo[5,4-d]thiazole guests(G1–G3) were encapsulated by cucurbit[8]uril(Q[8]) to construct Q[8]_(3)/G_(2) complexes, in which the encapsulated G molecules exist as an exact face-to-face dimer. These complexation behaviors have been indicated by proton nuclear magnetic resonance(~1H NMR) spectroscopy and isothermal titration calorimetry(ITC),and have been confirmed by X-ray single crystal structural analysis of Q[8]_(3)/G2_(2). While free guests G1–G3 have no ability to sensitize singlet oxygen, they all become effective singlet oxygen sensitizers when complexed with Q[8]. By irradiation of white light, Q[8]_(3)/G_(2) complexes induced selective oxidation of aryl sulfide to aryl sulfoxide in good yields and selective oxidation of dimethyl sulfide(DMS) to dimethyl sulfoxide(DMSO) in excellent yields without over-oxidation to dimethyl sulfone(DMSO_(2))even for elongated irradiation. High-yield photo-oxidation of DMS to DMSO_(2) was only achieved by irradiation of blue light in the presence of Q[8]_(3)/G1_(2), which was also effective in photobleaching of Rhodamine B in water. The higher photo-oxidation power of Q[8]_(3)/G1_(2) has been ascribed to an additional generation of reactive oxygen species besides singlet oxygen.

关键词： host-guest interaction dimerization macrocycles photosensitization

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Quantum properties of fermionic fields in multi-event horizon spacetime

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Science China(physics,Mechanics & Astronomy) 2023年第12期66卷 56-62页

作者： Qianqian Liu Shu-Min Wu Cuihong Wen Jieci Wang Department of Physics Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationHunan Normal UniversityChangsha 410081China Department of Physics Liaoning Normal UniversityDalian 116029China

We investigated the properties of quantum entanglement and mutual information in the multi-event horizon Schwarzschild-de Sitter(Sd S)spacetime for massless Dirac *** the first time,we obtained the expression for the evolutions of the quantum state near the black hole event horizon(BEH)and cosmological event horizon(CEH)in the Sd S *** the Nariai limit,the physically accessible entanglement and mutual information are maximized,and the physically inaccessible correlations are *** the increase in temperature of either horizon,the physically accessible correlations experience ***,the initial state remains entangled and can be utilized in entanglement-based quantum information processing tasks,which differs from the scalar field ***,the degradation of physically accessible correlations is more pronounced for small-mass black *** contrast,the physically inaccessible correlations separated by the CEH monotonically increase with the radiation temperature,and such correlations are not decisively influenced by the effect of particle creation at the ***,a similar phenomenon is observed for the inaccessible correlations separated by the *** result differs from the single event spacetime,in which the physically inaccessible entanglement is a monotonic function of the Hawking temperature.

关键词： multi-event horizon spacetime Dirac field SdS spacetime quantum entanglement

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Electron-transporting boron-doped polycyclic aromatic hydrocarbons:Facile synthesis and heteroatom doping positions-modulated optoelectronic properties

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Chinese Chemical Letters 2024年第4期35卷 447-451页

作者： Tingting Huang Zhuanlong Ding Hao Liu Ping-An Chen Longfeng Zhao Yuanyuan Hu Yifan Yao Kun Yang Zebing Zeng Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringHunan UniversityChangsha 410082China Shenzhen Research Institute of Hunan University Shenzhen 518000China Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education and Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices School of Physics and Electronics Hunan UniversityChangsha 410082China

While heteroatom doping serves as a powerful strategy for devising novel polycyclic aromatic hydrocarbons(PAHs), the further fine-tuning of optoelectronic properties via the precisely altering of doping patterns remains a challenge. Herein, by changing the doping positions of heteroatoms in a diindenopyrene skeleton, we report two isomeric boron, sulfur-embedded PAHs, named Anti-B_(2)S_(2) and Syn-B_(2)S_(2), as electron transporting semiconductors. Detailed structure-property relationship studies revealed that the varied heteroatom positions not only change their physicochemical properties, but also largely affect their solid-state packing modes and Lewis base-triggered photophysical responses. With their low-lying frontier molecular orbital levels, n-type characteristics with electron mobilities up to 1.5 × 10^(-3)cm^(2)V^(-1)s^(-1)were achieved in solution-processed organic field-effect transistors. Our work revealed the critical role of controlling heteroatom doping patterns for designing advanced PAHs.

关键词： Polycyclic aromatic hydrocarbon Optoelectronic properties Heteroatom doping n-Type organic semiconductors Structure–property relationship

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Energy Levels and Transition Rates for Laser Cooling Os-and a General Approach to Produce Cold Atoms and Molecules

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Chinese physics Letters 2023年第9期40卷 32-37页

作者：陆禹竹张瑞宋昌仙陈重阳司然宁传刚 Department of Physics State Key Laboratory of Low-Dimensional Quantum PhysicsTsinghua UniversityBeijing 100084China Shanghai EBIT Lab Key Laboratory of Nuclear Physics and Ion-Beam Application(MOE)Institute of Modern PhysicsDepartment of Nuclear Science and TechnologyFudan UniversityShanghai 200433China Frontier Science Center for Quantum Information Tsinghua UniversityBeijing 100084China

High-resolution photoelectron energy spectra of osmium anions are obtained using the slow-electron velocitymap imaging *** energy levels of excited states^(4)F_(7/2),^(4)F_(5/2)and^(4)F_(3/2)of Os-are determined to be 148.730(13),155.69(15),and 176.76(13)THz[or 4961.09(41),5193.4(49),and 5896.1(42)cm-1],*** lifetime of the opposite-parity excited state^(6)D^(o)_(9/2)is determined to be 201(10)μs using a cold ion trap,about 15 times shorter than the previous result 3(1)*** high-level multi-configuration Dirac–Hartree–Fock calculations yield a theoretical lifetime 527μ*** work shows that the laser cooling rate of Os-is as fast as that of Th-.The advantages of Os-are its near-IR range cooling transition and simple electronic structure,which make Os-a promising candidate for laser cooling of negative *** propose a general approach to produce cold atoms and molecules based on the sympathetic cooling of negative ions in combination with a threshold photodetachment.

关键词： method. excited lifetime

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Rational Design and Construction of a CdS QDs/lnVO_(4) Atomic-Layer(110)/(110)Facet S-Scheme Heterojunction for Highly Efficient Photocatalytic Degradation of C_(2)H_(4)

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Energy & Environmental Materials 2024年第3期7卷 211-218页

作者： Yuanpeng Dong Peizhu Ji Xinyue Xu Rong Li Yin Wang Kevin Peter Homewood Xiaohong Xia Yun Gao Xuxing Chen Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials School of Materials Science&EngineeringHubei UniversityWuhan 430062China Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices Hubei University of Arts and ScienceXiangyang 441053China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China United Water(Xianning)Company Limited Xianning 437100China

Exploring high efficiency S-scheme heterojunction photocatalysts with strong redox ability for removing volatile organic compounds from the air is of great interest and ***,how to predict and regulate the transport of photogenerated carriers in heterojunctions is a great ***,density functional theory calculations were first used to successfully predict the formation of a CdS quantum dots/InVO_(4)atomic-layer(110)/(110)facet S-scheme ***,a CdS quantum dots/InVO_(4)atomic-layer was synthesized by in-situ loading of CdS quantum dots with(110)facets onto the(110)facets of InVO_(4)*** a result of the deliberately constructed built-in electric field between the adjoining facets,we obtain a remarkably enhanced photocatalytic degradation rate for *** rate is 13.8 times that of pure CdS and 13.2 times that of pure InVO_(4).In-situ irradiated X-ray photoelectron spectroscopy,photoluminescence and time-resolved photoluminescence measurements were carried *** experiments validate that the built-in electric field enhanced the dissociation of photoexcited excitons and the separation of free charge carriers,and results in the formation of S-scheme charge transfer *** reaction mechanism of the photocatalytic C_(2)H_(4)oxidation is investigated by in-situ electron paramagnetic *** work provides a mechanistic insight into the construction and optimization of semiconductor heterojunction photocatalysts for application to environmental remediation.

关键词： CdS QDs InVO_(4)atomic-layer photocatalysis S-scheme volatile organic compounds

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