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Degradation of ferroelectric and weak ferromagnetic properties of BiFeO_3 films due to the diffusion of silicon atoms

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Chinese Physics B 2014年第7期23卷 712-716页

作者：肖仁政张早娣 vasiliy O.pelenovich 王泽松张瑞李慧刘雍黄志宏付德君 Key Laboratory of Artificial Micro- and Nano-Materials of Ministry of Education School of Physics and TechnologyWuhan University Department of Physics and Technology Huazhong Normal University

Crystalline BiFeO3 （BFO） films each with a crystal structure of a distorted rhombohedral perovskite are characterized by X-ray diffraction （XRD） and high-resolution electron microscopy （HRTEM）. The diffusion of silicon atoms from the substrate into the BiFeO3 film is detected by Rutherford backscattering spectrometry （RBS）. The element analysis is per- formed by energy dispersive X-ray spectroscopy （EDS）. Simulation results of RBS spectrum show a visualized distribution of silicon. X-ray photoelectron spectroscopy （XPS） indicates that a portion of silica is formed in the diffusion process of silicon atoms. Ferroelectric and weak ferromagnetic properties of the BFO films are degraded due to the diffusion of silicon atoms. The saturation magnetization decreases from 6.11 down to 0.75 emu/g, and the leakage current density increases from 3.8 × 10^-4 upto7.1 × 10^-4 A/cm-2.

关键词： ferroelectric ferromagnetic diffusion silicon

Optical and magnetic properties of InFeP layers prepared by Fe^+ implantation

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Chinese Physics B 2013年第10期22卷 397-400页

作者：周霖尚艳霞王泽松张瑞张早娣 vasiliy O.pelenovich 付德君 Kang Tae Won School of Physics and Technology Wuhan University Quantum-Functional Semiconductor Research Center Dongguk University

InFeP layers are prepared by ion implantation of InP with 100-keV Fe＋ ions to a dose of 5 ×10^16 cm-2 and investigated by optical, magnetic, and ion beam analysis measurements. Photoluminescence measurements show a deep-level peak at 1.035 eV due to Fe in InP and two exciton-related luminescences at 1.426 eV and 1.376 eV in the implanted samples annealed at 400℃. Conversion electron Mossbauer spectroscopy reveals a doublet corresponding to Fe3＋ ions in the indium sites. Atomic force microscopy and magnetic force microscopy show that magnetic clusters are formed in the annealing process. The magnetization-field hysteresis loops show ferromagnetic properties persisting up to room temperature with a coercive field of 100 0e （10e = 79.5775 A-m-1）, saturation magnetization of 4.35 × 10-5 emu, and remnant magnetization of 4.4× 10 6 emu.

关键词： ion implantation diluted magnetic semiconductor photoluminescence Rutherford backscatter-ing/channeling

Magnetooptics of non-Kramers Eu^(3+) ions in garnets:analysis complemented by crystal-field splitting modeling calculations

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Journal of Rare Earths 2013年第9期31卷 837-842页

作者： Uygun V.Valiev John B.Gruber Anvar K.Mukhammadiev vasiliy O.pelenovich 付德君 Gary W.Burdick Faculty of Physics National University of Uzbekistan Department of Physics and Astronomy The University of Texas at San Antonio School of Physics and Technology Wuhan University Department of Physics Andrews University

Spectra of absorption, luminescence, magnetic circular dichroism （MCD）, and magnetic circular polarization of lumines- cence （MCPL） in Gd3Ga5O12：Eu3＋ and Eu3Ga3O12 garnets were studied within the visible spectral range at 300 K. Analysis of the spectral and temperature dependences of the magnetooptical and optical spectra made it possible to identify the magneto-dipole （MD） and electro-dipole （ED） 4f→4f transitions occurring between Stark sublevels of the 7FJ （J=1, 2） and 5D0 multiplets in Eua＋-containing garnet structures. Quantum mechanical ＂mixing＂ had significant influence on quasi-degenerate states of the non-Kramers rare-earth Eu3＋ ion for Eu3GasOl2 in MCD due to forbidden MD transition 7F1→SD0 and for GdaGasOiE：EU3＋ in MCPL due to MD 4f→4f transition 5Do→7F1 and forced ED-transition 5Do→7F2. A parameterized Hamiltonian defined to operate within the entire 4f（6） ground electronic configuration of Eu3＋ ion was used to model the experimental Stark levels, including their irreducible rep- resentations and wavefunctions. The crystal-field parameters were determined through a Monte-Carlo method in which nine in- dependent crystal-field parameters, Bkq, were given random starting values and optimized using standard least-squares fitting between calculated and experimental levels. The final fitting standard deviation between 57 calculated-to-experimental levels was 0.73 meV.

关键词： : magnetic circular dichroism magnetic circular polarization luminescence adsorption garnet non-Kramers ion rare earths

Specific features of Eu^(3+) and Tb^(3+) magnetooptics in gadolinium-gallium garnet (Gd_3Ga_5O_(12))

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Journal of Rare Earths 2011年第8期29卷 776-782页

作者： Uygun V. Valiev John B. Gruber 付德君 vasiliy O. pelenovich Gary W. Burdick Mariya E. Malysheva Faculty of Physics National University of Uzbekistan Department of Physics and Astronomy The University of Texas at San Antonio Department of Physics Wuhan University Department of Physics Andrews University

We reported magnetooptical properties of Eu3＋（4f（6）） and Tb3＋（4f（8）） in single crystals of Gd3Ga5O12 （GGG）, Y3Ga5O12 （YGG）, and Eu3＋（4f（6）） in Eu3Ga5O12 （EuGG） for both ions occupying sites of D2 symmetry in the garnet structure. Absorption, luminescence, and magnetic circular polarization of luminescence （MCPL） spectra of Tb3＋ in GGG and YGG and absorption and magnetic circular dichroism （MCD） of Eu3＋ in EuGG were studied. The data were obtained at 85 K and room temperature （RT）. Magnetic susceptibility of Eu3＋ in EuGG was also measured between 85 K and RT. The magnetooptical and magnetic susceptibility data were modeled using the wavefunctions of the crystal-field split energy （Stark） levels of Eu3＋ and Tb3＋ occupying D2 sites in the same garnets. The results reported gave a precise determination of these Stark level assignments and confirmed the symmetry labels （irreducible representations） of the closely-spaced Stark levels （quasi-doublets） found in the 5D1 （Eu3＋） and 5D4 （Tb3＋） multiplets. Ultraviolet （UV） excitation （300 nm） of the 6PJ and 6IJ states of Gd3＋ in the doped GGG crystals led to emission from 5D4 （Tb3＋） and 5D1 and 5D0 （Eu3＋） through radiationless energy transfer to the 4f（n–1）5d band of Tb3＋ and to UV quintet states of Eu3＋. The temperature-dependent emission line shapes and line shifts of the magnetooptical transitions excited by UV radiation suggested a novel way to explore energy transfer mechanisms in this rare-earth doped garnet system.

关键词： magnetic circular polarization of luminescence magnetic circular dichroism absorption quantum qutting energy transfer magnetic susceptibility rare earths

Study of doping uniformity of a 200 kV ion implanter by RBS and sheet resistance measurements

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Nuclear Science and Techniques 2016年第3期27卷 40-44页

作者： Hui Li Ze-Song Wang Sheng-Jun Zhang vasiliy O.pelenovich Feng Ren De-Jun Fu Chuan-Sheng Liu Zhi-Wei Ai Key Laboratory of Artificial Micro-and Nano-Materials of Ministry of Education and School of Physics and Technology Wuhan UniversityWuhan 430072China Institute of Ion-Plasma and Laser Technologies Academy of Sciences of UzbekistanTashkent 700135Uzbekistan

The ion implantation uniformity is of vital importance for an ion *** this paper,we report the,uniformity measurement for a large current ion implanter(LC-16 type) by implanting of 190-keV Ar ions into Si to 3×1016 atoms/cm2,followed by Rutherford backscattering spectroscopy(RBS) and sheet resistance measurement providing quantitative information on spatial distribution of *** implant doses obtained from RBS at selected points of the sample give a spatial uniformity of <5%,which are confirmed by the sheet resistance *** sheet resistance is an indirect method for dose evaluation of ion-implanted samples,RBS provides a competent technique for calibration of the ion implantation *** both measurements show that good uniformity can be achieved for the ion implanter by tuning of the scanning process.

关键词：均匀性测量离子注入机薄层电阻掺杂分布 RBS 卢瑟福背散射离子注入系统剂量评价

Self-assembled high-entropy nitride multilayer coating

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Rare Metals 2024年第6期43卷 2876-2883页

作者： Xiang-Yu Zhang Yan Liu vasiliy pelenovich Xiao-Mei Zeng Jie Liu Qiang Wan Alexander Pogrebnjak Long-Jian Xue Zhi-Wen Chen Yan Lei Bing Yang School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China Hubei JiuFengShan Future Science and Technology Laboratory Wuhan 420000China Institute of Technological Sciences of Wuhan University Wuhan 430072China Hubei Key Laboratory of Electronic Manufacturing and Packaging Integration Wuhan UniversityWuhan 430072China College of Engineering Huazhong Agricultural UniversityWuhan 430070China Sumy State University Sumy 40007Ukraine Institute of Materials Science Slovak University of Technology in BratislavaJána Bottu2591724 TrnavaSlovak Republic Shenzhen Research Institute of Wuhan University Shenzhen 518057China

The development of advanced materials and construction of multilayer structure contribute to enhancing the performance of protective coatings,further improving the industrial productivity and conserving *** this paper,the self-assembled high-entropy nitride(HEN)AlCrNbSiTiN multilayer coating was designed by harnessing the plasma distribution characteristics and depos-ited by arc ion plating using single target.

关键词： coating energy multilayer

气体团簇离子束装置的设计及其在表面平坦化、自组装纳米结构中的应用

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物理学报 2020年第9期69卷 113-122页

作者：曾晓梅 vasiliy pelenovich Rakhim Rakhimov 左文彬邢斌罗进宝张翔宇付德君武汉大学物理科学与技术学院武汉430072 武汉大学动力与机械学院武汉430072

根据超声膨胀原理,n(10-10^4)个气体原子可以绝热冷却后凝聚在一起形成团簇,经过离化后,形成带一个电荷量的团簇离子,比如Arn^+.当团簇离子与固体材料相互作用时,由于平均每个原子携带的能量(~eV)较低,仅作用于材料浅表面区域,因此,气... 详细信息

根据超声膨胀原理,n(10-10^4)个气体原子可以绝热冷却后凝聚在一起形成团簇,经过离化后,形成带一个电荷量的团簇离子,比如Arn^+.当团簇离子与固体材料相互作用时,由于平均每个原子携带的能量(~eV)较低,仅作用于材料浅表面区域,因此,气体团簇离子束是材料表面改性的优良选择.本文介绍了一台由武汉大学加速器实验室自主研制的气体团簇离子束装置,包括整体构造、工作原理及实验应用.中性团簇束由金属锥形喷嘴(F=65-135μm,q=14°)形成,平均尺寸为3000 atoms/cluster,经离化后,其离子束流达到了50μ***团簇离子因其反应活性较低,本文运用Ar团簇离子(平均尺寸为1000 atoms/cluster)进行了平坦化和自组装纳米结构的研究.单晶硅片经Ar团簇离子束处理后,均方根粗糙度由初始的1.92 nm降低到0.5 nm,同时观察到了束流的清洁效应.利用Ar团簇离子束的倾斜(30°-60°)轰击,在宽大平坦的单晶ZnO基片上形成了纳米波纹,而在ZnO纳米棒表面则形成了有序的纳米台阶,同时,利用二维功率谱密度函数分析了纳米结构在基片上的表面形貌和特征分布,并计算了纳米波纹的尺寸和数量.

关键词：气体团簇离子束表面平坦化自组装纳米结构功率谱密度函数

离子剂量比在气体团簇多级能量平坦化模式中的作用

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物理学报 2021年第22期70卷 48-54页

作者：罗进宝 vasiliy pelenovich 曾晓梅郝中华张翔宇左文彬付德君武汉大学物理科学与技术学院武汉430072 武汉大学动力与机械学院武汉430072

本研究提出采用两种不同的离子剂量比的气体团簇离子束多级能量模式来改善n-Si(100)单晶片的创伤表面.模式一采用低剂量的高能量团簇和高剂量的低能量团簇组合,模式二则采用高剂量的高能量团簇和低剂量的低能量团簇组合.结果证明,模式... 详细信息

本研究提出采用两种不同的离子剂量比的气体团簇离子束多级能量模式来改善n-Si(100)单晶片的创伤表面.模式一采用低剂量的高能量团簇和高剂量的低能量团簇组合,模式二则采用高剂量的高能量团簇和低剂量的低能量团簇组合.结果证明,模式一的平坦化效果优于模式二,两者的均方根粗糙度分别为0.62 nm和1.02 nm.本文在研究多级能量模式平坦化前,先做了单一能量团簇轰击带有机械损伤的Si片实验,来验证创伤去除、离子损伤程度与团簇能量的关系.结果证明,当用15 kV高压加速团簇离子时,划痕去除效率最高,最终表面划痕很浅,但粗糙度下降不明显;当用8 kV,5 kV低压加速团簇离子时,样品表面变得细腻,遗留的离子损伤最轻.然后将多级能量模式一与单一能量团簇轰击靶材进行对比,结果表明,与单一15 keV的高能团簇处理相比,多级能量模式可以获得更为平坦的靶材表面;与单一5 keV的低能团簇处理相比,多级能量模式可以更好的去除划痕等创伤.多级能量模式一将高、低能团簇优点集中起来,从而达到最佳的平坦化效果.

关键词：气体团簇离子束表面平坦化离子剂量比多级能量模式表面粗糙度

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气体团簇离子束两步能量修形法的平坦化效应

物理学报 2021年第5期70卷 117-123页

作者： vasiliy pelenovich 曾晓梅罗进宝 Rakhim Rakhimov 左文彬张翔宇田灿鑫邹长伟付德君杨兵武汉大学物理科学与技术学院武汉430072 岭南师范学院物理科学与技术学院湛江524048 武汉大学动力与机械学院武汉430072

本文提出采用气体团簇离子束的两步能量修形法来改善4H-SiC(1000)晶片表面形貌.先用15 keV的高能Ar团簇离子进行整体修形,再用5 keV的低能团簇离子优化表面.结果表明,在相同的团簇离子剂量下,与单一15 keV的高能团簇处理相比,两步法修... 详细信息

本文提出采用气体团簇离子束的两步能量修形法来改善4H-SiC(1000)晶片表面形貌.先用15 keV的高能Ar团簇离子进行整体修形,再用5 keV的低能团簇离子优化表面.结果表明,在相同的团簇离子剂量下,与单一15 keV的高能团簇处理相比,两步法修形后的表面具有更低的均方根粗糙度,两者分别为1.05 nm和0.78 nm.本文还以原子级平坦表面为研究对象,揭示了载能团簇引起的半球形离子损伤(弧坑)与团簇能量的关系,及两步能量修形法在弧坑修复中的优势.在原子力显微镜表征的基础上,引入了二维功率谱密度函数,以直观全面地给出材料的表面形貌特征及其随波长(频率)的分布.结果表明,经任何能量的团簇离子轰击的表面,在0.05—0.20μm波长范围内,团簇轰击都能有效地降低粗糙度,而在0.02—0.05μm范围内,则出现了粗化效应,这是由于形成了半球形离子损伤,但第二步更低能量的团簇离子处理可以削弱这种粗化效应.

关键词：气体团簇离子束表面平坦化两步能量修形法表面粗糙度