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Two material removal modes in chemical mechanical polishing:mechanical plowing *** bonding

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Friction 2024年第5期12卷 897-905页

作者： Yuan WU Liang JIANG Wenhui LI Jiaxin ZHENG Yushan CHEN Linmao QIAN Tribology Research Institute State Key Laboratory of Rail Transit Vehicle SystemSouthwest Jiaotong UniversityChengdu610031China

With the rapid development of semiconductors,the number of materials needed to be polished sharply *** material properties vary significantly,posing challenges to chemical mechanical polishing(CMP).Accordingly,the study aimed to classify the material removal *** on the CMP and atomic force microscopy results,the six representative metals can be preliminarily classified into two groups,presumably due to different material removal *** the tribology perspective,the first group of Cu,Co,and Ni may mainly rely on the mechanical plowing *** adding H_(2)O_(2),corrosion can be first enhanced and then suppressed,affecting the surface mechanical ***,the material removal rate(MRR)and the surface roughness increase and *** comparison,the second group of Ta,Ru,and Ti may primarily depend on the chemical bonding *** H_(2)O_(2)can promote oxidation,increasing interfacial chemical ***,the MRR increases,and the surface roughness decreases and levels *** addition,CMP can be regulated by tuning the synergistic effect of oxidation,complexation,and dissolution for mechanical plowing,while tuning the synergistic effect of oxidation and ionic strength for chemical *** findings provide mechanistic insight into the material removal mechanism in CMP.

关键词： Chemical mechanical polishing corrosion wear material removal mode mechanical plowing chemical bonding

Direct observation of oxygen vacancy formation and migration over ceria surface by in situ environmental transmission electron microscopy

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Journal of Rare Earths 2024年第4期42卷 676-682页

作者： Dawei Pang Wei Li Ningqiang Zhang Hong He Shengcheng Mao Yanhui Chen Liwei Cao Chong Li Ang Li Xiaodong Han Beijing key laboratory of Solid Microstructure and Properties Department of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China Beijing key laboratory for Green Catalysis and Separation The Faculty of Environment and LifeBeijing University of TechnologyBeijing10124China International Joint Research laboratory for Quantum Functional Materials of Henan School of Physics and MicroelectronicsZhengzhou UniversityZhengzhou450001China

The extremely high structural tolerance of ceria to oxygen vacancies(Ov)has made it a desirable catalytic material for the hydrocarbon oxidation to chemicals and pharmaceuticals and the reduction of gaseous *** is proposed that the formation and diffusion of Ov originate from its outstanding reduction ***,the formation and diffusion process of Ov over the surface of ceria at the atomic level is still ***,the structural and valence evolution of CeO_(2)(111)surfaces in reductive,oxidative and vacuum environments from room temperature up to 700℃was studied with in situ aberration-corrected environmental transmission electron microscopy(ETEM)*** is found to form under a high vacuum at elevated temperatures;however,the surface can recover to the initial state through the adsorption of oxygen atoms in an oxygen-contained ***,in hydrogen environment,the step-CeO_(2)(111)surface is not stable at elevated temperatures;thus,the steps tend to be eliminated with increasing *** with first-principles density function calculations(DFT),it is proposed that O-terminated surfaces would develop in a hypoxic environment due to the dynamic diffusion of Ov from the outer surface to the ***,in a reductive environment,H2 facilitates the formation and diffusion of Ov while Ce-terminated surfaces *** results reveal dynamic atomic-scale interplay between the nanoceria surface and gas,thereby providing fundamental insights into the Ov-dependent reaction of nano-CeO_(2) during catalytic processes.

关键词： Ceria Direct observation In situ ETEM Oxygen vacancy Density function calculations Rareearths

Enhanced measurement precision with continuous interrogation during dynamical decoupling

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Chinese Physics B 2024年第3期33卷 88-94页

作者：张军杜鹏敬雷徐鹏尤力张文献 key laboratory of Artificial Micro- and Nano-structures of Ministry of Education and School of Physics and TechnologyWuhan UniversityWuhan 430072China State key laboratory of Low-Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084China Wuhan Institute of Quantum Technology Wuhan 430206China

Dynamical decoupling(DD)is normally ineffective when applied to DC *** its straightforward implementation,DD nulls out DC signal as well while suppressing *** work proposes a phase relay method that is capable of continuously interrogating the DC signal over many DD *** illustrate its efficacy when applied to the measurement of a weak DC magnetic field with an atomic spinor Bose-Einstein *** approaching standard quantum limit or Heisenberg limit are potentially realizable for a coherent spin state or a squeezed spin state of 10000 atoms,respectively,while ambient laboratory level noise is suppressed by *** work offers a practical approach to mitigate the limitations of DD to DC measurement and would find other applications for resorting coherence in quantum sensing and quantum information processing research.

关键词： quantum sensing continuous interrogation quantum magnetometer dynamical decoupling Heisenberg limit

Analyzing the surface passivity effect of germanium oxynitride:a comprehensive approach through first principles simulation and interface state density

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Nuclear Science and Techniques 2024年第5期35卷 74-84页

作者： Sheng-Jie Du Xiu-Xia Li Yang Tian Yuan-Yuan Liu Ke Jia Zhong-Zheng Tang Jian-Ping Cheng Zhi Deng Yu-Lan Li Zheng-Cao Li Sha-Sha Lv College of Nuclear Science and Technology Joint laboratory of Jinping Ultra‑Low Radiation Background Measurement of Ministry of Ecology and Environment key laboratory of Beam Technology of Ministry of Education Beijing Normal UniversityBeijing Normal UniversityBeijing 100875China Joint Research Center Nuctech Company LimitedBeijing 100084China Department of Engineering Physics Key Laboratory of Particle&Radiation Imaging of Ministry of EducationTsinghua UniversityBeijing 100084China key laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

High-purity germanium(HPGe)detectors,which are used for direct dark matter detection,have the advantages of a low threshold and excellent energy *** surface passivation of HPGe has become crucial for achieving an extremely low energy *** this study,first-principles simulations,passivation film preparation,and metal oxide semiconductor(MOS)capacitor characterization were combined to study surface *** calculations of the energy band structure of the -H,-OH,and -NH_(2) passivation groups on the surface of Ge were performed,and the interface state density and potential with five different passivation groups with N/O atomic ratios were accurately analyzed to obtain a stable surface *** on the theoretical calculation results,the surface passivation layers of the Ge_(2)ON_(2) film were prepared via magnetron sputtering in accordance with the optimum atomic ratio *** microstructure,C-V,and I-V electrical properties of the layers,and the passivation effect of the Al/Ge_(2)ON_(2)/Ge MOS were characterized to test the interface state *** mean interface state density obtained by the Terman method was 8.4×10^(11) cm^(-2) eV^(-1).The processing of germanium oxynitrogen passivation films is expected to be used in direct dark matter detection of the HPGe detector surface passivation technology to reduce the detector leakage currents.

关键词： Surface passivation High purity germanium detector Germanium nitrogen oxide Interface state density

Modification of POSS and their tribological properties and resistant to space atomic oxygen irradiation as lubricant additive of multialkylated cyclopentanes

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Friction 2024年第5期12卷 884-896页

作者： Xingwei WANG Chaoyang ZHANG Chen ZHAO Yijing LIANG Ming ZHANG Wufang YANG Bo YU Qiangliang YU Meirong CAI Feng ZHOU Weimin LIU State key laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China Shandong laboratory of Yantai Advanced Materials and Green Manufacturing Yantai264000China

Developing functional additive resistant to space atomic oxygen(AO)irradiation through simple molecular design and chemical synthesis to enhance the lubricating performance of multialkylated cyclopentanes(MACs)oil is a significant ***,sulfur-containing polyhedral oligomere silsesquioxane(POSS)were synthesize via a click-chemistry reaction of octavinyl polyhedral oligomeric with alkyl *** reduce-friction(RF),anti-wear(AW)properties and anti-AO irradiation of POSS-S-R as MACs base oil additives in atmospheric and simulated space environments were systematically investigated for the first *** demonstrate that POSS-S-R not only possesses outstanding anti-AO irradiation capacity but also effectively improves the RF and AW of MACs in atmospheric or simulated space *** improvement is due to the excellent anti-AO irradiation properties of the POSS structure itself and the high load-carrying ability of silicon-containing and sulfur-containing compounds generated by tribo-chemical reactions,which effectively separates the direct contact of the friction *** believe that this synthesized POSS-S-R is a promising additive for space lubricants.

关键词： POSS additive reduce-friction anti-wear multialkylated cyclopentanes(MACs) resistant atomic irradiation

Spatial quantum coherent modulation with perfect hybrid vector vortex beam based on atomic medium

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Chinese Physics B 2024年第2期33卷 360-364页

作者：马燕杨欣常虹杨鑫琪曹明涛张晓斐高宏董瑞芳张首刚 key laboratory of Time Reference and Applications National Time Service CenterChinese Academy of SciencesXi’an 710600China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Ministry of Education key laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter Shaanxi Key Laboratory of Quantum Information and Quantum Optoelectronic DevicesSchool of ScienceXi’an Jiaotong UniversityXi’an 710049China Department of Physics Shaanxi University of Science and TechnologyXi’an 710021China Hefei National laboratory Hefei 230088China

The perfect hybrid vector vortex beam(PHVVB)with helical phase wavefront structure has aroused significant concern in recent years,as its beam waist does not expand with the topological charge(TC).In this work,we investigate the spatial quantum coherent modulation effect with PHVVB based on the atomic medium,and we observe the absorption characteristic of the PHVVB with different TCs under variant magnetic *** find that the transmission spectrum linewidth of PHVVB can be effectively maintained regardless of the ***,the width of transmission peaks increases slightly as the beam size expands in hot atomic *** distinctive quantum coherence phenomenon,demonstrated by the interaction of an atomic medium with a hybrid vector-structured beam,might be anticipated to open up new opportunities for quantum coherence modulation and accurate magnetic field measurement.

关键词： perfect hybrid vector vortex beam topological charge quantum coherence optical manipulation

Stabilizing n-type cubic AgBiSe_(2) thermoelectric materials through alloying with PbS

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Journal of Materiomics 2024年第1期10卷 70-77页

作者： Lai Zhang Weixia Shen Zhuangfei Zhang Chao Fang Qianqian Wang Biao Wan Liangchao Chen Yuewen Zhang Xiaopeng Jia key laboratory of Material Physics of Ministry of Education School of Physics and MicroelectronicsZhengzhou UniversityZhengzhou450052China

Phase transition generates rapid changes of transport parameters and poor mechanical property,and thus restricts the application of thermoelectric ***_(2) exhibits cubic phase at above 580 K with high-symmetry structure and low lattice thermal conductivity,indicating the potentiality of high thermoelectric *** this work,the cubic structure of AgBiSe_(2) was achieved at ambient conditions by alloying with PbS,enhancing the configurational entropy at both cationic and anionic *** cubic structure was rather stable after several measurement *** substitution at cationic sites effectively reduced band gap,and increased both carrier concentration and effective *** samples exhibited relatively low lattice thermal conductivity(0.68-0.34 W/(m·K))in the temperature range of 300-773 K,due to the nanoscale inhomogeneity and the random distribution of multiple species at some atomic sites.A maximum zT of 0.65 at 773 K was obtained for(Ag_(0.99)Nb_(0.01)BiSe_(2))_(0.8)(PbS)_(0.2) *** entropy-driven structural stabilization is a promising strategy to achieve stable structure for practical thermoelectric applications.

关键词： Thermoelectric AgBiSe_(2) Configurational entropy Phase transition

Nanodiamond reinforced self-healing and transparent poly(urethane-urea)protective coating for scratch resistance

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International Journal of Smart and Nano Materials 2024年第1期15卷 75-94页

作者： Zhuochao Wang Wenxin Cao Chunqiang Sun Dongchao Ji Kunlong Zhao Gang Gao Xingchun Xu Yingqi Liu Tianyu Zhang Jiaqi Zhu Jiecai Han National key laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbinChina School of future technology Harbin institute of TechnologyHarbinChina key laboratory of Micro-systems and Micro-structures Manufacturing Ministry of EducationHarbinChina

With increasing demand for scratch-resistant flexible electro-nics,the development of transparent coatings with good scratch resistance and self-healing properties has emerged as a key research *** this study,a high-strength self-healing poly(urethane-urea)(PUU)-based nanocomposite coating was prepared by introducing functionalized nanodiamond(ND)into a PUU matrix via solution *** PUU matrix had hard-segment repeating units and was constructed using iso-phorone diamine and isophorone *** ND particles were modifed using a silane coupling agent,3-aminopropyl-triethoxysilane,to obtain well-dispersed KH-ND ***-ND promoted microphase separation in the PU matrix,inducing the formation of dense and homogeneous hard domains that dissipated stress,prevented further crack devel-opment,and improved the mechanical properties and scratch resistance of the *** addition,the coating exhibited excellent self-healing ***-transform infrared spectroscopy,scanning electron microscopy,and atomic force microscopy were used to characterize the self-healing and hardening mechanisms of the *** environmentally friendly PUU/KH-ND coating is easy to prepare and has broad application prospects in transparent and anti-scratch coatings for flexible electronics,automobiles,and home appliances.

关键词： Nanocomposite coatings self-healing scratch resistance transparent poly(urethane-urea)

Collaborative integration of Fe-N_(x)active center into defective sulfur/selenium-doped carbon for efficient oxygen electrocatalysts in liquid and flexible Zn-air batteries

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Chinese Chemical Letters 2024年第9期35卷 421-425页

作者： Yufeng Wu Mingjun Jing Juan Li Wenhui Deng Mingguang Yi Zhanpeng Chen Meixia Yang Jinyang Wu Xinkai Xu Yanson Bai Xiaoqing Zou Tianjing Wu Xianyou Wang National Base for International Science&Technology Cooperation National Local Joint Engineering Laboratory for Key Materials of New Energy Storage BatteryKey Laboratory of Environmentally Friendly Chemistry and Application of Ministry of EducationXiangtan UniversityXiangtan 411105China

Strategic active site organization is imperative for the advancement of effective and long-lasting catalysts of oxygen reduction ***,the controllable multi-active site design is a highly intricate topic for catalyst *** pre-trapping and post-activation strategy,Fe-N bonding structure and S,Se functionalized heteroatom are integrated into a conductive porous *** this process,the nitrogen-abundant polymer 1,3,5-triformylbenzene-tris(4-aminophenyl)benzene(Tf-TAPA)adsorbs Fe^(3+)under the intrinsically metal anchoring ability of N atoms and simultaneously in-situ assembles longchain ***,the Fe^(3+)is transformed into Fe-N_(x)moieties with the conversion of the organic chain to incompletely graphitized ***,the alteration of the electronic configuration achieved through the introduction of dual-atom S and Se leads to a pronounced enhancement in catalytic *** from the Fe-N_(x)bonding structure,dense structural defects,and conductive carbon networks,the resultant Fe-S,Se/NCNs possesses a positive half-wave potential of 0.86 V and a 90%current retention rate,outstripping the Pt/C ***,the liquid and flexible ZAB driven by Fe-S,Se/NCNs achieves large power densities of 259.7 and 164.7 m W/cm^(2),*** study provides a new comprehension in developing an efficient and stable M-N-C oxygen electrocatalyst.

关键词： atomic regulation Chalcogens co-doped Catalytic performance Noble metal-free electrocatalyst Zn-air battery