Effects of silicon nitride diffusion barrier on germanium MOS capacitors with HfON gate dielectrics

MOS capacitors with hafnium oxynitride (HfON) gate dielectrics were fabricated on Ge and Si substrates using the RF reactive magnetron sputtering method. A large amount of fixed charges and interface traps exist at the Ge/HfON interface. HRTEM and XPS analyses show that Ge oxides were grown and diffused into HfON after post metal annealing. A Si nitride interfacial layer was inserted between Ge and HfON as diffusion barrier. Using this method, well behaved capacitance-voltage and current-voltage characteristics were obtained. Finally hystereses are compared under different process conditions and possible causes are discussed.     

Structural Aspects of P2-Type Na0.67Mn0.6Ni0.2Li0.2O2 (MNL) Stabilization by Lithium Defects as a Cathode Material for Sodium-Ion Batteries

A known strategy for improving the properties of layered oxide electrodes in sodium-ion batteries is the partial substitution of transition metals by Li. Herein, the role of Li as a defect and its impact on sodium storage in P2-Na_0.67Mn_0.6Ni_0.2Li_0.2O₂ is discussed. In tandem with electrochemical studies, the electronic and atomic structure are studied using solid-state NMR, operando XRD, and density functional theory (DFT). For the as-synthesized material, Li is located in comparable amounts within the sodium and the transition metal oxide (TMO) layers. Desodiation leads to a redistribution of Li ions within the crystal lattice. During charging, Li ions from the Na layer first migrate to the TMO layer before reversing their course at low Na contents. There is little change in the lattice parameters during charging/discharging, indicating stabilization of the P2 structure. This leads to a solid-solution type storage mechanism (sloping voltage profile) and hence excellent cycle life with a capacity of 110 mAh g^-1 after 100 cycles. In contrast, the Li-free compositions Na_0.67Mn_0.6Ni_0.4O₂ and Na_0.67Mn_0.8Ni_0.2O₂ show phase transitions and a stair-case voltage profile. The capacity is found to originate from mainly Ni³⁺/Ni⁴⁺ and O^2-/O^2-δ redox processes by DFT, although a small contribution from Mn⁴⁺/Mn⁵⁺ to the capacity cannot be excluded.     

栅氧化层TDDB可靠性评价试验及模型参数提取

采用恒定电压和恒定电流试验方法对20nm栅氧化层进行了TDDB可靠性评价试验，并完成了1／E模型参数提取，给出了恒定电流应力下描述氧化层TDDB退化的统计模型，较好地解释了试验结果。     

锰钴镍氧浸没式探测器制备及性能

基于化学溶液法制备了尖晶石结构氧化物锰钴镍氧Mn1.56Co0.96Ni0.48O4(MCNO)薄膜材料,研究了其电学性质及红外器件的探测性能,包括器件的响应率,时间常数和探测率.制作了厚度为8μm的MCNO薄膜及红外热敏探测器件,测量了材料的阻值-温度曲线.制作了基于半球形锗透镜的浸没式MCNO薄膜探测器,具有时间常数较小(~18 ms),响应率高(~4.4×103V/W)和探测率高(~5×108cm·Hz0.5/W)的优点.     

测辐射热计的微桥研制和Vox膜成膜研究

介绍了测辐射热汁的工作原理、器件结构的几何形状和研制状况,叙述了测辐射热计材料的特性及制备技术.     

Bioinspired Magnetite Crystallization Directed by Random Copolypeptides

Control over magnetite (Fe₃O₄) formation is difficult to achieve in synthetic systems without using non‐aqueous media and high temperatures. In contrast, Nature employs often intrinsically disordered proteins to tightly tailor the size, shape, purity, and organization of the nanocrystals to optimize their magnetic properties. Inspired by such “flexible polyelectrolytes,” here random copolypeptides having different amino acid compositions are used as control agents in the bioinspired coprecipitation of magnetite through a ferrihydrite precursor, following a recently developed mineralization protocol. Importantly, the copolypeptide library is designed such that the amino acid composition can be optimized to simultaneously direct the size of the nanoparticles as well as their dispersibility in aqueous media in a one‐pot manner. Acidic amino acids are demonstrated to regulate the crystal size by delaying nucleation and reducing growth. Their relative content thus can be balanced to tune between the superparamagnetic and ferrimagnetic regimes, and high contents of negatively charged amino acids result in colloidal stabilization of superparamagnetic nanoparticles at high pH. Conversely, with positively charged lysine‐rich copolypeptides ferrimagnetic crystals are obtained which are stabilized at neutral pH and self‐organize in chains, as visualized by cryo‐transmission electron microscopy. Altogether, the presented findings give important insights for the future development of additive‐mediated nanomaterial syntheses.     

某高岭土细尾矿酸浸除铁的研究

研究了用草酸漂白除去高岭土细尾矿中高含量的氧化铁。结果表明 ,草酸能够溶解高岭土中的可浸铁 ,当 p H值低于 1.2 ,浸取温度为 80℃ ,用草酸浸取除铁后 ,高岭土细尾矿的白度达80 % ,达到了工业应用的基本要求。     

Phase Diagram of the BaO-CuO Binary System

The phase diagram of the BaO-CuO binary system has been investigated in air and in a mixed gas of Ar + 0.21 atm of O₂. The existence of two compounds, BaCuO₂ and Ba₂CuO₃, was confirmed. The phase transition of Ba₂CuO₃ from an orthorhombic to a tetragonal phase was observed to occur at 1083 K. The lattice constants of the tetragonal Ba₂CuO₃ phase were determined to be a = 1.2975 nm and b = 0.3992 nm. BaCuO₂ was shown to melt incongruently by a synthetic reaction at 1289 K. Furthermore, the existence of two eutectic reactions and a peritectic reaction in the present system was confirmed.     

Transition Metal Oxide Work Functions: The Influence of Cation Oxidation State and Oxygen Vacancies

Transition metal oxides are capable of a wide range of work functions. This quality allows them to be used in many applications that involve charge transfer with adsorbed molecules, for example as heterogeneous catalysts, as charge‐injection layers in organic electronics, and as electrodes in fuel cells. Chemical and structural factors can alter transition‐metal oxide work functions, often making their work functions difficult to control. Little is known about the effects of the cation oxidation state and point defects on the oxide work function. It is necessary to understand how such chemical and structural factors affect work functions in order to controllably tune transition metal oxides for desired applications. Here, a correlation between the oxide work function and cation oxidation state is demonstrated. This correlation is attributed to the change in cation electronegativity with oxidation state. A model is presented that relates the work function to the oxygen deficiency for d⁰ oxides in the limit of dilute oxygen vacancies. It is proposed that the rapid initial decrease in work function, observed for d⁰ oxides, is caused by an increase in the density of donor‐like defect states. It is also shown that oxides tend to have decreased work functions near a metal/metal‐oxide interface as a consequence of the relationship between defects and work function. These insights provide guidelines for tuning transition metal oxide work functions.     

Organic Diamine-Regulated Vanadium Oxides as Cathode Materials for High-Performance Sodium Ion Batteries

Pre-intercalating ions between V O layers is considered to be an effective strategy to modulate the interlayer spacing of 2D vanadium oxides. However, the rigid pre-intercalated ions hardly keep stable during repeated charging/discharging process and their sizes limit the extent of interlayer spacing expansion, which inevitably lead to poor rate capability and cycle stability. In this work, aliphatic diamines are adopted as pre-intercalated guests to elastically modulate the interlayer spacing of V O layers by tuning the chain length of the organic diamine molecules. Benefiting from the strong interaction between the terminal doubly protonated amine and the polar negative oxygen bridge of the V O layers, the aliphatic diamine molecules can act as a structural stabilizer between the layers and boost fast Na ion diffusion (10⁻⁸ to 10⁻¹⁰ cm² s⁻¹). The sodium ion battery based on the first synthesized 1,6-hexanediamine pre-intercalated vanadium oxide supported on nickel foam hybrid cathode achieves a large specific capacity of 597 mAh g⁻¹ at 0.09 A g⁻¹, as well as superior rate performance and cycling stability. This work provides a strategy to elastically modulate 2D layered materials with tunable interlayer spacing for batteries based on large-size-ions.