Superlattices and Microstructures最新文献

英文中文

Ultrasonication-assisted fabrication of porous ZnO@C nanoplates for lithium-ion batteries 锂离子电池用多孔ZnO@C纳米板的超声辅助制备

IF 3.1 3区物理与天体物理 Q2 PHYSICS, CONDENSED MATTER

Superlattices and Microstructures

Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2022.11

Xueting Wang, Yunchuang Wang, Mei-Yueh Wu, Ruopian Fang, Xi Yang, Da-Wei Wang

Lithium-ion batteries have made significant commercial and academic progress in recent decades. Zinc oxide (ZnO) has been widely studied as a lithium-ion battery anode due to its high theoretical capacity of 987 mAh g-1, natural abundance, low cost, and environmental friendliness. However, ZnO suffers from poor electronic conductivity and large volume variation during the battery discharge/charge process, leading to capacity deterioration during long-term cycling. Herein, porous ZnO@C nanoplates are developed to offer short ion diffusion pathways and good conduction networks for both Li ions and electrons. The porous nanoplates provide abundant active sites for electrochemical reactions with minimized charge transfer impedance. As a result, the porous ZnO@C nanoplates deliver higher performance for lithium-ion storage compared with a bare ZnO anode. Furthermore, with the introduction of reduced graphene oxide (rGO), the ZnO@C@rGO composite anode achieves a capacity of 229.3 mAh g-1 at a high current density of 2 A g-1.

近几十年来，锂离子电池在商业和学术上都取得了重大进展。氧化锌(ZnO)具有理论容量高达987 mAh g-1、天然丰度高、成本低、环境友好等优点，作为锂离子电池负极材料得到了广泛的研究。但在电池充放电过程中，ZnO的电子导电性差，体积变化大，在长期循环过程中会导致容量下降。在此，开发了多孔ZnO@C纳米板，为Li离子和电子提供了短的离子扩散途径和良好的传导网络。多孔纳米板以最小的电荷转移阻抗为电化学反应提供了丰富的活性位点。因此，与裸ZnO阳极相比，多孔ZnO@C纳米板具有更高的锂离子存储性能。此外，随着还原氧化石墨烯(rGO)的引入，ZnO@C@rGO复合阳极在2 a g-1的高电流密度下实现了229.3 mAh g-1的容量。

引用次数: 2

A critical review of the mechanical properties of CoCrNi-based medium-entropy alloys cocrni基中熵合金力学性能综述

IF 3.1 3区物理与天体物理 Q2 PHYSICS, CONDENSED MATTER

Superlattices and Microstructures

Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2021.10

Ding Xu, Mingliang Wang, Tianxin Li, Xiang Wei, Yiping Lu

The CoCrFeMnNi alloy is one of the most notable first-generation high-entropy alloys and is also known as a Cantor alloy. This alloy was first proposed in 2004 and shows promising performance at cryogenic temperatures (CTs). Subsequent research has indicated that the equiatomic ternary CoCrNi medium-entropy alloy (MEA), as a subset of the Cantor alloy family, has better mechanical properties than the CoCrFeMnNi alloy. Interestingly, both the strength and ductility of the CoCrNi MEA are higher at CTs than at room temperature. CoCrNi-based alloys have attracted considerable attention in the metallic materials community and it is therefore important to generalize and summarize the latest progress in CoCrNi-based MEA research. The present review initially briefly introduces the discovery of the CoCrNi MEA. Subsequently, its tensile response and deformation mechanisms are summarized. In particular, the effects of parameters, such as critical resolved shear stress, stacking fault energy and short-range ordering, on the deformation behavior are discussed in detail. The methods for strengthening the CoCrNi MEA are then reviewed and divided into two categories, namely, modifying microstructures and adjusting chemical compositions. In addition, the mechanical performance of CoCrNi-based MEAs, including their dynamic shear properties, creep behavior and fracture toughness, is also deliberated. Finally, the development prospects of CoCrNi-based MEAs are proposed.

CoCrFeMnNi合金是最著名的第一代高熵合金之一，也被称为康托合金。该合金于2004年首次提出，在低温(ct)下表现出良好的性能。随后的研究表明，等原子三元CoCrNi中熵合金(MEA)作为Cantor合金家族的一个分支，具有比CoCrFeMnNi合金更好的力学性能。有趣的是，CoCrNi MEA在ct下的强度和延展性都比室温下高。cocrni基合金在金属材料界引起了广泛的关注，因此总结和总结cocrni基MEA研究的最新进展具有重要意义。本文首先简要介绍了CoCrNi MEA的发现。总结了其拉伸响应和变形机理。重点讨论了临界分解剪应力、层错能和短程有序等参数对材料变形行为的影响。综述了强化CoCrNi MEA的方法，并将其分为两类，即改变微观结构和调整化学成分。此外，还研究了cocrni基MEAs的力学性能，包括动态剪切性能、蠕变性能和断裂韧性。最后，展望了基于cocrni的mea的发展前景。

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引用次数: 29

Influence of softening annealing on microstructural heredity and mechanical properties of medium-Mn steel 软化退火对中锰钢组织遗传和力学性能的影响

IF 3.1 3区物理与天体物理 Q2 PHYSICS, CONDENSED MATTER

Superlattices and Microstructures

Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2022.01

Fanglin Ding, Qinyi Guo, B. Hu, H. Luo

Softening annealing (SA) is often required for producing medium-Mn steels (MMS) as it lowers hardness so that they can be cold rolled to reduce thickness. The influences of different SA processes on the microstructural heredity during the processing route and the final tensile properties were studied. It was found that the SA process could either intensify or weaken the influence of the Mn segregation resulting from solidification on the subsequent microstructural evolution during the process, i.e., microstructural heredity. In the case when no SA was employed, both recrystallization and rapid growth of ferrite grains preceded the reverse austenitic transformation during the intercritical annealing (IA) in the Mn-lean regions, where very coarse ferrite grains were formed. This deteriorated ductility was due to the propagation of cracking along the boundary of the coarse-grained and fine-grained regions. In contrast, SA at a sufficiently high temperature could dissolve cementite, producing uniformly distributed austenite grains. They transformed to martensite during cold rolling but were reborn during IA. As a result, ultrafine austenite and ferrite grains were uniformly distributed, which improved ductility significantly. This study hints at a new approach to altering the microstructural heredity resulting from the heterogeneous Mn distribution in MMS.

软化退火(SA)通常需要生产中锰钢(MMS)，因为它降低硬度，使他们可以冷轧，以减少厚度。研究了不同的SA工艺对加工过程中组织遗传和最终拉伸性能的影响。结果表明，SA工艺可以增强或减弱凝固过程中Mn偏析对后续组织演变的影响，即组织遗传。在不使用SA的情况下，在贫锰区(Mn-lean area)的临界间退火(IA)过程中，铁素体晶粒的再结晶和快速生长先于反奥氏体转变，在那里形成了非常粗的铁素体晶粒。这种恶化的延性是由于裂纹沿粗晶和细晶区域的边界扩展。相反，SA在足够高的温度下可以溶解渗碳体，产生均匀分布的奥氏体晶粒。它们在冷轧过程中转变为马氏体，但在IA过程中重生。超细奥氏体和铁素体晶粒均匀分布，显著提高了塑性。本研究提示了一种新的方法来改变MMS中锰分布不均导致的微观结构遗传。

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引用次数: 0

Microstructural evolution and ferroelectricity in HfO2 films HfO2薄膜的微观结构演变和铁电性

IF 3.1 3区物理与天体物理 Q2 PHYSICS, CONDENSED MATTER

Superlattices and Microstructures

Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2021.11

Dou Zhao, Zibin Chen, Xiaozhou Liao

Ferroelectric (FE) materials, which typically adopt the perovskite structure with non-centrosymmetry and exhibit spontaneous polarization, are promising for applications in memory, electromechanical and energy storage devices. However, these advanced applications suffer from the intrinsic limitations of perovskite FEs, including poor complementary metal oxide semiconductor (CMOS) compatibility and environmental issues associated with lead. Hafnium oxide (HfO2), with stable bulk centrosymmetric phases, possesses robust ferroelectricity in nanoscale thin films due to the formation of non-centrosymmetric phases. Owing to its high CMOS compatibility and high scalability, HfO2 has attracted significant attention. In the last decade, significant efforts have been made to explore the origin of the ferroelectricity and factors that influence the FE properties in HfO2 films, particularly regarding the role of microstructure, which is vital in clarifying these issues. Although several comprehensive reviews of HfO2 films have been published, there is currently no review focused on the relationship between microstructure and FE properties. This review focuses on the microstructure-property relationships in FE polycrystalline and epitaxial HfO2 films. The crystallographic structures and characterization methods for HfO2 polymorphs are first discussed. For polycrystalline HfO2 films, the microstructure-FE properties relationships, driving force and kinetic pathway of phase transformations under growth parameters or external stimuli are reviewed. For epitaxial films, the lattice matching relations between HfO2 films and substrates and the corresponding impact on the FE properties are discussed. The FE properties between polycrystalline and epitaxial HfO2 films are compared based on their different microstructural characteristics. Finally, a future perspective is given for further investigating FE HfO2 films.

铁电材料通常采用非中心对称的钙钛矿结构，具有自发极化特性，在存储器、机电和储能器件中具有广阔的应用前景。然而，这些先进的应用受到钙钛矿FEs固有局限性的影响，包括互补金属氧化物半导体(CMOS)兼容性差以及与铅相关的环境问题。具有稳定体中心对称相的氧化铪(HfO2)在纳米级薄膜中由于非中心对称相的形成而具有强大的铁电性。由于其高CMOS兼容性和高可扩展性，HfO2备受关注。在过去的十年中，人们已经做出了巨大的努力来探索铁电性的起源和影响HfO2薄膜中FE性能的因素，特别是关于微观结构的作用，这对于澄清这些问题至关重要。虽然已经发表了几篇关于HfO2薄膜的综合综述，但目前还没有关于微观结构与FE性能之间关系的综述。本文综述了FE多晶和外延HfO2薄膜的微观结构-性能关系。首先讨论了HfO2多晶的晶体结构和表征方法。综述了多晶HfO2薄膜在生长参数或外界刺激下的微观结构- fe性能关系、相变的驱动力和动力学途径。对于外延薄膜，讨论了HfO2薄膜与衬底之间的晶格匹配关系及其对FE性能的影响。基于不同的微观结构特征，比较了多晶和外延HfO2薄膜的FE性能。最后，对FE - HfO2薄膜的进一步研究进行了展望。

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引用次数: 9

Environmental embrittlement behavior of high-entropy alloys 高熵合金的环境脆化行为

IF 3.1 3区物理与天体物理 Q2 PHYSICS, CONDENSED MATTER

Superlattices and Microstructures

Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2022.26

引用次数: 1

K6Sn4F12I2•0.5H2O: a zero-dimensional alkali metal tin mixed halide compound exhibiting color change due to crystal water loss K6Sn4F12I2•0.5H2O:一种因结晶水损失而变色的零维碱金属锡混合卤化物化合物

IF 3.1 3区物理与天体物理 Q2 PHYSICS, CONDENSED MATTER

Superlattices and Microstructures

Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2021.07

P. Gong, S. Luo, Zheshuai Lin

a zero-dimensional metal tin mixed halide compound exhibiting color change due to crystal water loss. Abstract A new zero-dimensional alkali-metal tin mixed halide, K 6 Sn 4 F 12 I 2 • 0.5H 2 O, is synthesized by a hydrothermal method. It crystallizes in the cubic centrosymmetric space group of Fd-3m (No. 227) and its structure consists of crystal water molecules and ordered arranged [Sn 4 F 12 I 4 ] fundamental structural blocks trapped in [K 18 ] cages. Interestingly, K 6 Sn 4 F 12 I 2 • 0.5H 2 O exhibits a color change from colorless to orange when exposed to air. Experimental measurements combined with theoretical calculations reveal that the color change in K 6 Sn 4 F 12 I 2 • 0.5H 2 O is attributed to the loss of crystal water.

一种零维金属锡混合卤化物化合物，由于结晶水的损失而表现出颜色变化。摘要:采用水热法合成了一种新的零维碱金属锡混合卤化物k6sn 4f12i2•0.5 h2o。它在Fd-3m(227号)的立方中心对称空间群中结晶，其结构由结晶水分子和被囚禁在[K 18]笼中的有序排列的[Sn 4 F 12 I 4]基本结构块组成。有趣的是，k6 Sn 4 f12 I 2•0.5 h2o暴露在空气中，呈现出从无色到橙色的变化。实验测量与理论计算相结合表明，k6sn4f12i2•0.5 h2o的颜色变化是由于结晶水的损失造成的。

引用次数: 0

Tuning the bandgap of Cd1-xZnxS (x = 0~1) buffer layer and CIGS absorber layer for obtaining high efficiency 调整Cd1-xZnxS (x = 0~1)缓冲层和CIGS吸收层的带隙以获得高效率

IF 3.1 3区物理与天体物理 Q2 PHYSICS, CONDENSED MATTER

Superlattices and Microstructures

Pub Date : 2022-01-01 DOI: 10.1016/j.spmi.2021.107100

T. Hossain , M.K. Sobayel , F.T. Munna , S. Islam , H.I. Alkhammash , Khaled Althubeiti , S.M. Jahangir Alam , K. Techato , Md. Akhtaruzzaman , M.J. Rashid

This numerical study deals with the CIGS solar cell considering Cd_1-xZn_xS buffer layer. The composition ‘x’ of the buffer layer is determined and its impact on the solar cell performance parameters is studied. The influence of the buffer layer thickness on quantum efficiency is also discussed. The tuned bandgap and optimized thickness of the Cd_1-xZn_xS buffer layer are then utilized to obtain the suitable bandgap of the CIGS absorber layer. The maximum power conversion zone is revealed in terms of the CIGS bandgap and the impact of this bandgap on spectral response as well as performance parameters are discussed. The Cd_0.6Zn_0.4S/CIGS interface is studied by varying the defect density from 10¹⁰ cm⁻³ to 10¹⁶ cm⁻³. The cell performances are also analyzed for the temperature ranging from 260 K to 350 K.

本文对考虑Cd1-xZnxS缓冲层的CIGS太阳能电池进行了数值研究。确定了缓冲层的组成，并研究了其对太阳能电池性能参数的影响。讨论了缓冲层厚度对量子效率的影响。然后利用调整后的带隙和优化后的Cd1-xZnxS缓冲层厚度来获得合适的CIGS吸收层带隙。从CIGS带隙的角度揭示了最大功率转换区域，并讨论了该带隙对光谱响应和性能参数的影响。研究了Cd0.6Zn0.4S/CIGS界面缺陷密度在1010 ~ 1016 cm−3范围内的变化。在260k ~ 350k的温度范围内分析了电池的性能。

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引用次数: 10

An insight into growth transition in AlN epitaxial films produced by metal-organic chemical vapour deposition at different growth temperatures 金属-有机化学气相沉积制备的AlN外延膜在不同生长温度下的生长转变

IF 3.1 3区物理与天体物理 Q2 PHYSICS, CONDENSED MATTER

Superlattices and Microstructures

Pub Date : 2022-01-01 DOI: 10.1016/j.spmi.2021.107095

M.A.A.Z. Md Sahar , Z. Hassan , S.S. Ng , N.A. Hamzah , Y. Yusuf , N.N. Novikova , V.A. Yakovlev , S.A. Klimin

This work demonstrates a clear picture growth transition of aluminium nitride (AlN) films from the three-dimensional (3D) to the two-dimensional (2D) regime on the sapphire substrate at various temperatures using metal-organic chemical vapour deposition (MOCVD) under low reactor pressure. The high deposition rate of large 3D AlN islands that isolated each other change to 2D growth mode with a smoother surface as temperature increases from 800 °C to 1340 °C. From x-ray diffraction measurement, the AlN (100), AlN (002), and AlN (101) planes exhibit strong peak monocrystalline AlN (002) films as the temperature increase. It found that the AlN film grew at 1100 °C in the Frank–van der Merwe or 2D growth mode exhibits the highest crystalline quality with the threading dislocation density around 2.21 × 10⁹ cm⁻². In addition, the lattice vibrational parameters of the AlN films at 1100 °C shows the lowest phonon damping from IR spectra results. Thus, this study details the AlN epitaxial films growth transition, which is crucial for growing high crystalline quality AlN layer using the MOCVD technique.

本研究在低反应器压力下，利用金属有机化学气相沉积(MOCVD)技术，在不同温度下，在蓝宝石衬底上，清晰地展示了氮化铝(AlN)薄膜从三维(3D)到二维(2D)的生长转变。当温度从800°C升高到1340°C时，相互隔离的大型三维AlN岛的高沉积速率转变为二维生长模式，表面更光滑。x射线衍射测量表明，随着温度的升高，AlN(100)、AlN(002)和AlN(101)平面呈现出强单晶AlN(002)薄膜。结果表明，在1100℃下以Frank-van der Merwe或2D生长方式生长的AlN薄膜具有最高的晶体质量，其线位错密度约为2.21 × 109 cm−2。此外，从红外光谱结果来看，1100℃时AlN薄膜的晶格振动参数表现出最低的声子阻尼。因此，本研究详细介绍了AlN外延膜的生长转变，这对于使用MOCVD技术生长高结晶质量的AlN层至关重要。

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引用次数: 4

Comprehensive review on electrical noise analysis of TFET structures TFET结构电噪声分析综述

IF 3.1 3区物理与天体物理 Q2 PHYSICS, CONDENSED MATTER

Superlattices and Microstructures

Pub Date : 2022-01-01 DOI: 10.1016/j.spmi.2021.107101

Sweta Chander, Sanjeet Kumar Sinha, Rekha Chaudhary

Tunnel Filed Effect Transistors (TFETs) have appeared as an alternative for conventional CMOS due to their advantages like very low leakage current and steep sub-threshold slope. In semiconductor devices, noise is considered an undesired signal that can deteriorate the desired signal. In TFET structures different noise sources affect the performance at different frequency ranges. This paper presents a comprehensive review of impact of electrical noise on the performance of various TFET structures. The impact of both low-frequency noise sources and high-frequency sources have been discussed thoroughly. The study of different types of electrical noises occur in simple TFET device and different structures of TFET is presented.

隧道场效应晶体管(tfet)由于其极低的漏电流和陡峭的亚阈值斜率等优点而成为传统CMOS的替代品。在半导体器件中，噪声被认为是一种不希望的信号，它会使期望的信号变差。在TFET结构中，不同的噪声源会影响其在不同频率范围内的性能。本文综述了电噪声对各种TFET结构性能的影响。对低频噪声源和高频噪声源的影响进行了深入的讨论。研究了在简单的TFET器件中产生的不同类型的电噪声和不同的TFET结构。

引用次数: 21

Recent advances in two-dimensional van der Waals magnets 二维范德华磁体的最新进展

IF 3.1 3区物理与天体物理 Q2 PHYSICS, CONDENSED MATTER

Superlattices and Microstructures

Pub Date : 2022-01-01 DOI: 10.20517/microstructures.2022.02

Hang Xu, Shengjie Xu, Xun Xu, J. Zhuang, W. Hao, Yi Du

Two-dimensional (2D) magnets have evoked tremendous interest within the research community due to their fascinating features and novel mechanisms, as well as their potential applications in magnetic nanodevices. In this review, state-of-the-art research into the exploration of 2D magnets from the perspective of their magnetic interaction and order mechanisms is discussed. The properties of these magnets can be effectively modulated by varying the external parameters, such as the charge carrier doping, thickness effect, pressure and strain. The potential applications of heterostructures of these 2D magnets in terms of the interlayer coupling strength are reviewed, and the challenges and outlook for this field are proposed.

二维(2D)磁体由于其迷人的特性和新颖的机制以及在磁性纳米器件中的潜在应用而引起了研究界的极大兴趣。在这篇综述中，从磁性相互作用和有序机制的角度讨论了二维磁体的最新研究进展。通过改变载流子掺杂、厚度效应、压力和应变等外部参数，可以有效地调节这些磁体的性能。综述了异质结构二维磁体在层间耦合强度方面的潜在应用，并提出了该领域的挑战和展望。

引用次数: 14

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