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Experimental charge density distribution and its correlation to structural and optical properties of Sm^3＋ doped Nd2O3 nanophosphors

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Journal of Rare Earths 2017年第11期35卷 1102-1114页

作者： Morris Marieli Antoinette S. Israel G. Sathya Arlin Jose Amali John L. Berchmans K. Sujatha C. Anzline R. Niranjana Devi Post Graduate and Research Department of Physics Tile American College Madurai 625 002 Tamilnadu India Electro-Pyrometallurgy Division CS1R-Central Electrochemical Research Institute Karaikudi 630003 Tamilnadu India School of Chemistry Madurai Kamaraj University Madurai 625021 Tamilnadu India

Pure and Smdoped NdOnanophosphors were synthesized using modified Pechini method. The phase formation with symmetry of the sample is confirmed by the Rietveld refinement of the powder Xray diffraction(PXRD) data. The surface morphology and the crystallite size were examined using scanning electron microscopy(SEM) and transmission electron microscopy(TEM) and the results confirmed that the synthesized particles are in nanosize. The energy-dispersive X-ray(EDX) analysis was done to confirm the purity of the sample. The optical properties of the sample were studied using ultraviolet-visible range(UV-Vis) spectroscopic analysis and photoluminescence studies. The calculated band gap of the synthesized NdOwas found to be higher than that of bulk NdO. The photoluminescence(PL) of the prepared samples reveals that doping with Sm3+ ion has influenced the optical properties. Quantitative investigation on charge density distribution was done by analysing the 3-dimensional and 2-dimensional charge density maps drawn along the bonding directions. The maximum entropy method(MEM)/Rietveld analysis was used for the first time to analyse the charge density in the chosen system. charge density arrangement in the unit cell is correlated to the analysed photoluminescent(PL) properties. The spectral behaviour of the samples has been explained through charge ordering which are verified using experimental data obtained. The studies on these materials have shown that these nanophosphors will provide promising application for near-ultraviolet lightemitting diodes(n-UV-LEDs).

关键词： Modified Pechini method Photoluminescence MEM/Rietveld charge density

High Resolution Synchrotron Diffraction Study on charge density Distribution of Ampicillin Trihydrate

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Chinese Journal of Chemical Physics 2017年第1期30卷 50-62,I0001页

作者： C. Anzline S. lsrael R. Niranjana Devi R. A. J, R.Sheeba P. Richard Rajkumar Research and Postgraduate Department of Physics The American college Madurai 625002 Tamil Nadu India Mother Teresa Women＇s University Kodaikanal 624102 Tamil Nadu India Research and Postgraduate Department of Physics Madura College Madurai 625001 Tamil IVadu India

charge density distribution in ampicillin trihydrate was investigated experimentally. Results were compared with the quantum calculations using density functional theory. The charge derived properties including Mulliken atomic charges, dipole moment, and molecular electrostatic potential were calculated. The multipole analysis was done for the refinement of experimental population parameters. The structure factors obtained from multipole treat- ment were used for the construction of Fourier maps. Topological properties of the charge distribution were discussed and the characteristics of （3, -1） critical points were analyzed.

关键词： charge density Multipole analysis density functional theory Electrophilicity index

Influence of nitrogen dose on the charge density of nitrogen-implanted buried oxide in SOI wafers

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Journal of Semiconductors 2010年第2期31卷 99-102页

作者：郑中山刘忠立李宁李国花张恩霞 Department of Physics University of Jinan Institute of Semiconductors Chinese Academy of Sciences College of Material Engineering Shanghai University of Engineering Science

To harden silicon-on-insulator（SOI） wafers fabricated using separation by implanted oxygen（SIMOX） to total-dose irradiation,the technique of nitrogen implantation into the buried oxide（BOX） layer of SIMOX wafers can be ***,in this work,it has been found that all the nitrogen-implanted BOX layers reveal greater initial positive charge densities,which increased with increasing nitrogen implantation ***,the results indicate that excessively large nitrogen implantation dose reduced the radiation tolerance of BOX for its high initial positive charge density. The bigger initial positive charge densities can be ascribed to the accumulation of implanted nitrogen near the Si-BOX interface after *** the other hand,in our work,it has also been observed that,unlike nitrogen-implanted BOX,all the fluorine-implanted BOX layers show a negative charge *** obtain the initial charge densities of the BOX layers,the tested samples were fabricated with a metal-BOX-silicon（MBS） structure based on SIMOX wafers for high-frequency capacitance-voltage（C-V） analysis.

关键词： buried oxide charge density nitrogen implantation fluorine implantation

Complexation between DNA and Peptides with Precisely Controlled charge density and Distribution

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Chinese Journal of Polymer Science 2014年第11期32卷 1460-1468页

作者： Ji-han Zhou Hao Wen Cui-cui Su Lin Niu 梁德海 Beijing National Laboratory for Molecular Sciences and the Key Laboratory of Polymer Chemistry and Physics of Ministry of Education College of Chemistry and Molecular EngineeringPeking University

Using three designed peptides with precisely-controlled charge density and three types of DNAs with different length and flexibility, the effect of charge density on the formation of PEC was studied. Highly charged（KKKK）5 interacts strongly with 21 bp ds DNA to form large complex, followed by precipitation; while the medium charged（KGKG）5 only form complex with 21 bp ds DNA at proper ＋/- charge ratios; and no prominent complex between weakly charged（KGGG）5 and 21 bp ds DNA is observed at the same conditions. Similar trend is observed when the peptides form complex with 2000 bp DNA or 21 nt ssD NA. It is also found that the complex formed by adding peptide to DNA is in random coil conformation, but the complex prepared by the inverse order is in molten globule state. Re-dissolution of the complex occurs only when DNA is added to peptides with similar or shorter length.

关键词： Peptide charge density DNA Polyelectrolyte complex.

Analytic Solution of charge density of Single Wall Carbon Nanotube under Conditions of Field Electron Emission

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Chinese Physics Letters 2006年第6期23卷 1616-1618页

作者：李志兵王伟良 The State Key Laboratory of Optoelectronic Materials and Technologies Department of Physics Sun-Yat-sen University Guangzhou 510275

We derive the analytic solution of induced electrostatic potential along single wall carbon nanotubes. Under the hypothesis of constant density of states in the charge-neutral level, we are able to obtain the linear d... 详细信息

关键词： Analytic Solution charge density Field Electron Emission

Influence of charge density and Chain Length on the Interaction between Organic Anion and Montmorillonite

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Journal of Wuhan University of Technology(Materials Science) 2013年第1期28卷 6-11页

作者：郑俊萍 LI Jian HAO Hui YAO Kangde Tianjin Key Laboratory of Composite and Functional Materials School of Materials Science and Engineering Tianjin University

Anionic surfantant sodium dodecyl sulfate （SDS）, cationic surfactant cetyl trimethyl ammonium bromide （CTAB） and acrylic acid （AA） were introduced as molecular models to study the interaction between montmorillonite and organic molecules with different charge or chain length. The compounds were characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FT-IR） and 13C nuclear magnetic resonance （13C NMR）. The results show organic anion could interact strongly with montmorillonite, even the molecules could intercalate into the layers of MMT.

关键词： chain length charge density interaction montmoriUonitc.

Analysis of charge density and Fermi level of Al In Sb/In Sb single-gate high electron mobility transistor

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Journal of Semiconductors 2015年第6期36卷 47-52页

作者： S.Theodore Chandra N.B.Balamurugan M.Bhuvaneswari N.Anbuselvan N.Mohankumar National Instruments Electronics Laboratory Department of ECE Thiagarajar College of Engineering Department of ECE SKP Engineering College

A compact model is proposed to derive the charge density of the AlInSb/InSb HEMT devices by con- sidering the variation of Fermi level, the first subband, the second subband and sheet carrier charge density with applied gate voltage. The proposed model considers the Fermi level dependence of charge density and vice versa. The analytical results generated by the proposed model are compared and they agree well with the experimental results. The developed model can be used to implement a physics based compact model for an InSb HEMT device in SPICE applications.

关键词： charge density Fermi level high electron mobility transistor 2D analytical model

Specific Heat and charge density of Quasi-One-Dimensional Interchain Coupling Organic Ferromagnets

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Communications in Theoretical Physics 2008年第12期50卷 1435-1438页

作者： WANG Zhong-Long YAO Kai-Lun Department of Physics Huazhong University of Science and Technology Wuhan 430074 China Science College China Three Gorges University Yichang 443002 China International Center of Materials Physics The Chinese Academy of Sciences Shengyang 110015 China

On the basis of a generalized SSH model, an organic polymer ferromagnet theory is proposed at the finite temperature in the self-consistent mean field approximation, and the specific heat and charge density of the quasione-dimensional interehain coupling organic ferromagnets are presented. We find that an obvious feature is to present itself the round peak for the specific heat with the temperature. This indicates unambiguously the presence of the phase transition in the system. The transition temperature plays down with increasing of the interchain coupling t2 or decreasing of the electron repulsion u. The curves of charge density with the temperature debase monotonously. This result illustrates that the higher the temperature is, the more electrons are excited.

关键词： specific heat charge density organic ferromagnets

Engineering Ru(IV)charge density in Ru@RuO2 core-shell electrocatalyst via tensile strain for efficient oxygen evolution in acidic media

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Chinese Journal of Catalysis 2020年第8期41卷 1161-1167页

作者： Yizhi Wen Tao Yang Chuanqi Cheng Xueru Zhao Enzuo Liu Jing Yang Institute of New-Energy Materials Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of EducationSchool of Materials Science and EngineeringTianjin UniversityTianjin 300072China

The design of efficient Ru-based electrocatalysts with high intrinsic activities for acidic water oxidation is highly desirable and challenging for water splitting in proton exchange membrane ***,for the first time,we engineer the charge density of Ru(IV)by creating tensile strains in the RuO2 shell of Ru@RuO2 core-shell nanoparticles,***@***-resolution spectroscopic characterizations confirm the presence of av.6%tensile strain in Ru-O bonds,which results in an effective reduction of the Ru(IV)charge *** resultant Ru^X+(4charge density of Ru(IV),and the rapid charge transport owing to the Ru ***@RuO2-L also demonstrates high feasibility as the anode catalyst for the overall water splitting in acidic media.

关键词： Tensile strain Core-shell structure Ruthenium oxide charge density Oxygen evolution reaction Acidic media