以LiCoO2为阴极的全固态薄膜锂电池的研究

采用射频磁控溅射技术制备了非晶态和不同取向的多晶LiCoO2薄膜,利用XRD和SEM研究了不同温度退火后LiCoO2薄膜的结构和形貌.以具有不同结构的LiCoO2薄膜为阴极、含氮磷酸锂薄膜为电解质以及金属锂薄膜为阳极,成功地制备了电化学性能不同的全固态薄膜锂电池.由电化学研究结果表明,LiCoO2薄膜的结构和多晶取向决定了薄膜电池的电化学性能.采用具有一定取向的多晶LiCoO2薄膜制备的全固态薄膜锂电池具有最佳的性能,稳定放电容量达到55.4μAh/cm2μm,充放电循环次数超过450次.     

Si(100)衬底上Mg_(0.33)Zn_(0.67)O薄膜的结构及光学性能

采用射频磁控溅射法在Si(100)衬底上制备了Mg_(0.33)Zn_(0.67)O薄膜,研究了Mg_(0.33)Zn_(0.67)O薄膜的结构和光学性能。结果表明,Si(100)衬底上Mg_(0.33)Zn_(0.67)O薄膜呈六方纤锌矿结构,薄膜沿c方向取向生长,且c轴方向晶格增大0.03 nm。薄膜呈现优异的半导体特性,激子吸收峰位于297 nm,禁带宽度约为4.3 eV。薄膜平均粒径约为20 nm。薄膜在深紫外激发下的荧光发射位于368 nm。     

射频磁控溅射法制备薄膜电池电极的计算机模拟初步

计算机模拟仿真射频磁控溅射实验制备薄膜及离于电池电极,研究了在特定实验条件下薄膜的生长过程,并分析了影响薄膜生长的部分因素。     

(Ni0.8Zn0.2Fe2O4)epoxy-PZT双层膜中的磁电效应

讨论了Ni0.8Zn0.2Fe2O4(NZFO)与锆钛酸铅(PZT)的双层膜结构样品的磁电(ME)效应.NZFO粉料由溶胶-凝胶法制成,再经900℃热压,并高温烧结.在该双层膜中测量到了很强的磁电相互作用.发现横向的磁电效应比纵向效应大一个数量级,并且随NZFO烧结温度的提高而增加.当烧结温度从950℃上升到1380℃时,横向ME电压系数(αE)的最大值变化范围为25.6 mV Am-2≤αE≤199.6 mV Am-2.理论分析显示NZFO-PZT双层膜样品中ME效应源于NZFO与PZT之间相对良好的磁电耦合.     

蓝宝石衬底SnO2:Sb薄膜的制备及结构和光致发光性质

用射频磁控溅射法在蓝宝石(0001)衬底上制备出锑掺杂的氧化锡(SnO2:sb)薄膜.对制备薄膜的结构和发光性质进行了研究.制备样品为多晶薄膜,具有纯SnO2的四方金红石结构.室温条件下对样品进行光致发光测量,在334 nm附近观测到紫外发射峰,并对SnO2:Sb的光致发光机制进行了研究.     

外延PbZr0.2Ti0.8O3薄膜负电容的应变调控

为了让摩尔定律能够延续下去,降低功耗是很多研究者关注的问题,铁电负电容效应的发现为其提供了一种解决方案.应变工程作为调控铁电薄膜物理性能的有效手段已经被广泛研究.但是应变对铁电负电容调控的相关机理并不清楚.本文通过Landau-Khalatnikov方程模拟了应变场和温度场对PbZr0.2Ti0.8O3铁电薄膜负电容的...     

Si(001)基片上反应射频磁控溅射ZnO薄膜的两步生长方法

利用反应射频磁控溅射技术,采用两步生长方法制备了ZnO薄膜,探讨了基片刻蚀时间和低温过渡层沉积时间对ZnO薄膜生长行为的影响.研究结果表明,低温ZnO过渡层的沉积时间所导致的薄膜表面形貌的变化与过渡层在Si(001)表面的覆盖度有关.当低温过渡层尚未完全覆盖基片表面时,ZnO薄膜的表面岛尺度较小、表面粗糙度较大,薄膜应力较大;当低温过渡层完全覆盖Si(001)基片后,ZnO薄膜的表面岛尺度较大、表面粗糙度较小,薄膜应力较小.基片刻蚀时间对薄膜表面形貌的影响与低温过渡层的成核密度有关.随着刻蚀时间的增加,ZnO薄膜的表面粗糙度逐渐下降,表面形貌自仿射结构的关联长度逐渐减小.关键词：ZnO薄膜反应射频磁控溅射两步生长形貌分析     

重电子金属CeCu5.8 M0.2(M=Ni,Zn,Cd) 低温物性的比较

研究了不同元素等量掺杂下重电子金属CeCu5.8M0.2(M=Ni,Zn,Cd)低温电阻、比热容和磁化率随温度的变化关系.分析讨论了掺杂元素M(M=Ni,Zn,Cd)的磁性、价态及原子尺寸对近藤温度Tk、相干温度(即电阻极大值的温度TRmax)、每个Ce离子在较高温度时的平均磁矩μB以及在温度降低时被传导电子自旋屏蔽过程的影响.     

沉积温度、膜厚对Ce0.8Gd0.2O2-δ薄膜的微结构和电导率影响

采用脉冲激光沉积法在MgO(100)单晶衬底上制备了Ce0.8Gd0.2O2-δ(CGO)系列薄膜,沉积温度与膜厚对CGO/MgO薄膜的微结构及离子电导率的影响分别被研究.X-ray衍射(2θ-ω线扫描,ω-摇摆曲线,(-扫描)测量显示,随着沉积温度的升高,CGO薄膜的微结构由多晶薄膜演变到外延膜.对沉积在730℃的CGO薄膜(510nm)中较大的离子电导归因于薄膜中较小的晶界密度.对高质外延的CGO薄膜(沉积730℃),随着膜厚的减小,其快速减小的激活能及增大的离子电导可解释为CGO/MgO界面平面的应变态和氧空位的无序分布所致.我们的结果表明,为获得高离子电导的CGO薄膜,最佳的沉积温度和膜厚是需要考虑的.     

薄膜结构对Si／SiO2 I-V特性的影响

用射频磁控溅射法制备了3种结构的Si／SiO2纳米薄膜,测定了薄膜的I-V特性．实验结果分析表明,薄膜结构是影响其FV特性的主要因素．     

Polyaspartic-acid-pyrolysis route for the synthesis of nanocrystalline LiCo<Subscript>0.15</Subscript>Mn<Subscript>1.85</Subscript>O<Subscript>4</Subscript> powder for Li-ion batteries

Nanocrystalline cubic spinel LiCo_0.15Mn_1.85O₄ powder was prepared by a novel method based on in situ polymerization of aspartic acid along with metal salts. Thermal study shows that the complete crystallization and/or formation of the compound is at 358 °C. The structural property of the synthesized material was characterized by X-ray diffraction studies. The X-ray diffractogram reveals the single-phase formation of the product. Scanning electron microscope study shows that the average grain size of the powder is less than 1 μm. To assess the electrochemical performance of the synthesized cathode material, the C/LiCo_0.15Mn_1.85O₄ cell with 1 M LiPF₆ in 1:1 (v/v) mixture of ethylene carbonate and dimethyl carbonate as the electrolyte was assembled, and the charge and discharge studies were made in between 3.0 and 4.8 V at a constant current density of 0.1 mAcm⁻². It shows that capacity loss is only 2% even after the 50th cycle. As this preparation method is simple and particularly suitable for preparation of highly homogeneous mixed metal oxides for Li-ion batteries.     

射频溅射沉积硅薄膜实验

本文描述采用射频溅射法在GH39不锈钢基体上沉积硅薄膜的实验。对直接溅射沉积硅薄膜的工艺进行了实验研究,并对硅膜进行了SIMS分析。用称重法测出无定形硅膜的最大厚度可达400—500nm,为HL-1装置等离子体边界层物理实验制作了所需的无定形硅膜收集探针。     

Lithium electrochemistry of SiO2 thin film electrode for lithium-ion batteries

The lithium electrochemistry of SiO₂ thin film prepared by reactive radio frequency sputtering has been investigated for the first time. The reversible discharge capacities of SiO₂/Li cells cycled between 0.01 and 3.0 V are found in the range from 416 to 510 mAh/g during the first 100 cycles. By using ex situ transmission electron microscopy, selected-area electron diffraction and X-ray photo-electron spectroscopy measurements, both Li-Si alloying process and the reversible conversion reaction of SiO₂ into Li₂Si₂O₅ are proposed in the lithium electrochemical reaction of SiO₂. SiO₂ film electrode with high-reversible capacity and good cycle performance exhibits it potential anode material for future lithium-ion batteries.     

用SiC薄膜作防氚渗透阻挡层的研究

采用分步偏压辅助射频溅射法在316L不锈钢表面制备SiC薄膜,作为聚变堆第一壁及包层结构材料的氚渗透阻挡层,扫描电镜观察表明,制备的膜致密,均匀,且与基体结合牢固。X射线衍射分析表明,膜具有（111）面择优取向的β-SiC微晶结构。傅里叶变换红外光谱分析发现,对应于β-SiC的Si-C键存在伸缩振动吸收峰,采用中间复合过渡层技术,可以提高SiC膜与不锈钢基体的结合强度。测量了500℃时带有SiC膜的316L不锈钢的氚渗透率,与表面镀钯膜的316L相比,氚渗透率减低因子（PRF）值达到10^4以上,溅射时衬底偏压和射频功率要影响膜的结构,从而影响PRF值,根据分析结果,从不同的膜制备工艺中初步筛选出了合适工艺。     

室温下溅射法制备高迁移率氧化锌薄膜晶体管

为降低氧化锌薄膜晶体管（ZnOTFT）的工作电压,提高迁移率,采用磁控溅射法在氧化铟锡（ITO）导电玻璃基底上室温下依次沉积NbLaO栅介质层和ZnO半导体有源层,制备出ZnOTFT,对器件的电特性进行了表征。该ZnOTFT呈现出优异的器件性能：当栅电压为5V、漏源电压为10V时,器件的饱和漏电流高达2.2mA;有效场效应饱和迁移率高达107cm²/（V·s）,是目前所报道的室温下溅射法制备ZnOTFT的最高值,亚阈值摆幅为0.28V/decade,开关电流比大于10⁷。利用原子力显微镜（AFM）对NbLaO和ZnO薄膜的表面形貌进行了分析,分析了器件的低频噪声特性,对器件呈现高迁移率、低亚阈值摆幅以及迟滞现象的机理进行了讨论。

     

Preparation of boron carbon nitride thin films by radio frequency magnetron sputtering

Boron carbon nitride films were deposited by radio frequency magnetron sputtering using a composite target consisting of h-BN and graphite in an Ar-N₂ gas mixture. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The results suggest that the films are atomic-level hybrids composed of B, C and N atoms. The boron carbon nitride films prepared in the present experiment have a disordered structure. The sputtering power varied from 80 W to 130 W. This sputtering power was shown to have regular effect on the composition of boron carbon nitride films. The samples deposited at 80 W and 130 W are close to the stoichiometry of BC₃N. The sample deposited at 110 W is close to the stoichiometry of BCN. The samples deposited at 100 W and 120 W approach to BC₂N. It is very significant for us to synthesize boron carbon nitride compound with controllable composition by changing the sputtering power.     

Blue-violet luminescence double peak of In-doped films prepared by radio frequency sputtering

ZnO films doped with different contents of indium were prepared by radio frequency sputtering technique. The structural, optical and emission properties of the films were characterized at room temperature using XRD, XPS, UV-vis-NIR and PL techniques. Results showed that the indium was successfully incorporated into the c-axis preferred orientated ZnO films, and the In-doped ZnO films are of over 80% optical transparency in the visible range. Furthermore, a double peak of blue-violet emission with a constant energy interval (∼0.17 eV) was observed in the PL spectra of the samples with area ratio of indium chips to the Zn target larger than 2.0%. The blue peak comes from the electron transition from the Zn_i level to the top of the valence band and the violet peak from the In_Zn donor level to the V_Zn level, respectively.     

Li-ion migration in Li2FeSiO4-related cathode materials: A DFT study

The orthosilicate family of materials Li₂MSiO₄ for M = Fe, Mn and Co are coming to be seen as potentially cheap cathode materials for large-scale Li-ion batteries, not least through the possibility for significant capacity gains if more than one Li-ion can be removed per formula unit. To gain insights into possible Li-ion migration pathways and diffusion barriers for Li-ions, model systems for Li_xFeSiO₄ (x ≈ 1, 2) are here studied using the Density Functional Theory (DFT) approach. Li-ion and ion-vacancy migration barriers are calculated for a number of model systems. The results help explain why the Li/Fe site-mixing observed during electrochemical cycling of Li₂FeSiO₄ does not lead to any noticeable loss in cell performance, despite the increased tortuosity introduced into the Li-migration pathways by this ion-mixing process.