硼碳氮薄膜的制备及其光透过性质研究

利用射频磁控溅射方法以不同的氮气分压比（1/10-2/3）在玻璃衬底上制备出一组硼碳氮薄膜.傅里叶变换红外光谱测量发现样品的组成原子之间均实现了原子级化合.氮气分压比对薄膜的组分和透过率有很大影响,其通过改变薄膜组分而影响透过率,并且碳原子数小的样品具有较高的透过率.     

Electrical properties of sulfur-implanted cubic boron nitride thin films

Cubic boron nitride(c-BN)thin films were deposited on Si substrates by applying ion beam assisted deposition and then doped by S ion implantation.To produce a uniform depth profile of S ions in c-BN films,the implantation was carried out for the multiple energies.A slight degradation of c-BN crystallinity resulted from ion implantation can be recovered by thermal annealing,keeping the cubic phase content as high as 92%.The resistance reduces from 1010X for the as-deposited c-BN film to 108X after an S implantation of 5 9 1014ions cm-2and annealing at 1,173 K,suggesting an electrical doping effect of S dopant.The electrical resistance of the S-doped c-BN thin film decreases with increasing temperature,indicating semiconductor characteristics.The activation energy of S dopant is estimated to be 0.28±0.01 eV from the temperature dependence of resistance.     

射频功率对硼碳氮薄膜的组分和厚度的影响

利用射频磁控溅射方法以不同的射频功率(80～130 W)在硅衬底上制备出一组硼碳氮(BCN)薄膜.傅里叶红外吸收光谱(FTIR)和X射线光电子能谱(XPS)测量发现样品的组成原子之间均实现了原子级化合.射频功率对薄膜的组分和厚度有很大影响,二者随射频功率的增大而呈规律性变化.B、N元素含量高、C元素含量低的硼碳氮薄膜较厚.并且,射频功率为110 W条件下制备的硼碳氮薄膜中C元素含量最低,薄膜最厚.     

氮气分压比对硼碳氮薄膜的组分及光学带隙的影响

采用射频磁控溅射方法以不同的氮气分压比(1/10～2/3)制备出一组硼碳氮薄膜.傅里叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)测量发现样品的组成原子之间均实现了原子级化合.XPS测量结果表明,所有样品中的B、N原子比近似为1:1,其化学配比为BCx N(0.16＜x＜1.46).紫外/可见/近红外分光光度计用于测量样品的吸收光谱.由吸收谱线在低能区域(2.0～3.0 eV)的光吸收,利用关系作图法求出光学带隙Eopt范围为0.17～0.83 eV.氮气分压比对薄膜的组分和光学带隙有很大影响,其通过改变薄膜组分而影响光学带隙,并且碳原子数小的样品具有较宽的光学带隙.以氮气分压比为1/3条件下制备的样品中碳原子数最小,它的光学带隙最宽为0.83 eV.     

Structure and stability of boron nitride cages

The structure and energy of boron nitrides,(BN)n (n=10-41), have been investigated theoretically. The most stable cages have been constructed on the basis of a simple design principle, and the predicated stability has been validated at the B3LYP/6-31G^* level of theory. Among these,the Th symmetrical (BN)12 cluster has been confirmed to be the most stable cage on the basis of the calculated disproportation energy and binding energy per BN unit.     

Layered boron nitride as a release layer for mechanical transfer of GaN-based devices

Nitride semiconductors are the materials of choice for a variety of device applications, notably optoelectronics and high-frequency/high-power electronics. One important practical goal is to realize such devices on large, flexible and affordable substrates, on which direct growth of nitride semiconductors of sufficient quality is problematic. Several techniques--such as laser lift-off--have been investigated to enable the transfer of nitride devices from one substrate to another, but existing methods still have some important disadvantages. Here we demonstrate that hexagonal boron nitride (h-BN) can form a release layer that enables the mechanical transfer of gallium nitride (GaN)-based device structures onto foreign substrates. The h-BN layer serves two purposes: it acts as a buffer layer for the growth of high-quality GaN-based semiconductors, and provides a shear plane that makes it straightforward to release the resulting devices. We illustrate the potential versatility of this approach by using h-BN-buffered sapphire substrates to grow an AlGaN/GaN heterostructure with electron mobility of 1,100?cm(2)?V(-1)?s(-1), an InGaN/GaN multiple-quantum-well structure, and a multiple-quantum-well light-emitting diode. These device structures, ranging in area from five millimetres square to two centimetres square, are then mechanically released from the sapphire substrates and successfully transferred onto other substrates.     

氮化铁薄膜的结构及磁性研究

采用直流磁控溅射方法，以Ar／N2作为放电气体在玻璃基片上沉积了单相γFe4N薄膜，采用X射线衍射（XRD）和超导量子干涉仪（SQUID）对所制备的样品进行了结构和磁性性能分析，研究了基片温度对薄膜的结构和磁性性能的影响。     

应力条件下单壁氮化硼纳米管结构、力学和电学性质

采用第一性原理赝势平面波方法,研究了单壁氮化硼(BN)纳米管在应力条件下的结构、力学和电学性质。计算了不同类型氮化硼纳米管的弹性模量、拉伸强度和Poisson比。结果表明:氮化硼纳米管具有与碳纳米管相同量级的弹性模量(TPa量级)和拉伸强度(GPa量级),可以当作稳定的基体材料用于复合材料的合成中。同时发现:在拉伸情况下,氮化硼纳米管的结构和能带结构均发生一定规律的变化,能隙逐渐减小。这表明,氮化硼纳米管可以用作nm级别的力学传感器。     

碳氮化合物硬质薄膜的结构与摩擦性能

碳氮化合物（ＣＮ）是经理论预测的、硬度有可能超过金刚石的非天然共价化合物。该文使用反应离化团束（ＲＩＣＢ）方法,以低分子量聚乙烯为蒸发源材料,氮气为反应气体,在Ｓｉ（１１１）衬底上生长了ＣＮ薄膜。用激光喇曼（Ｒａ－ｍａｎ）散射分析了薄膜中的成键情况。结果表明,当氮气分压为１３．３ｍＰａ时,在波数１２４８ｃｍ－１附近出现源于共价Ｎ—Ｃ单键的喇曼峰,而且该峰强度随氮气分压的增加而增加。这个结果与Ｘ射线光电子能谱（ＸＰＳ）分析结果是一致的。硬度测定结果表明,生长的ＣＮ薄膜的努氏显微硬度最高可达６１ＧＰａ。在无润滑条件下进行滑动摩擦试验,测得的摩擦因数最低为～０．０８。     

石墨烯薄膜的化学气相法制备及光、电特性研究

利用化学气相沉积方法制备了石墨烯薄膜,并研究了其光电特性。以乙醇做反应原料、氩气作为携载气体,在873 K、973 K、1 073 K的温度下合成石墨烯薄膜。应用光学显微镜观察,发现在1 073 K时能够制备大面积均匀、平整光滑的石墨烯薄膜。纳曼光谱分析结果表明:制备的石墨烯薄膜出现2 650 cm-1的石墨烯的特征峰-D强峰,同时该峰强度随温度的升高而迅速增强,说明低温不能使沉积的碳原子有效的石墨化为石墨烯,而较高的温度有助于乙醇分解并石墨化为石墨烯薄膜。在1 073 K时沉积的石墨烯薄膜具有良好的光、电特性,其电子迁移率可以达到104 cm2.(V.s)-1,光透射率达97%,因此,可用于制备石墨烯晶体管、太阳能电池等光电子器件。     

Studies on Wear and corrosion resistances of carbon nitride thin films on Ti alloy

0　IntroductionArtificialarthrosiseshavebeenwidelyusedintheoperatorsclinicalsurgeriesforthepatientswhosearthrosiseswerese riouslyseverelydamaged.Butmostofartificialarthrosisescanon lybeusedforabouttenyearslongduetotheseriousabrasion .Forthisreason ,theimprovementofthelongevityofartificialarthrosisbecomesanimportantsubjectofstudy .TheartificialarthrosisesbeingmadeupofTialloyTC4(Ti 6Al 4V)andthepolythenewithultrahighmolecularweighthavegreatpotentialitiesonim provinglongevitybecauseTC4canreac…     

p-Si TFT的电场增强MILC制备技术

采用电场增强金属诱导侧向晶化方法获得了结晶良好的多晶硅薄膜,并采用该工艺制备了p沟道薄膜晶体管器件,其迁移率为65cm2/(V·s),开关态电流比为5×106.采用拉曼光谱分析、X射线衍射、扫描电镜等微观分析手段对多晶硅薄膜进行了分析,结果表明加电场于两电极之间有促进多晶硅薄膜晶化的作用.采用EFE-MILC技术获得了大的晶粒尺寸,并用此技术制备了p沟多晶硅TFT.表明EFE-MILC技术是在低温下获得大晶粒尺寸p-Si薄膜和高性能p-SiTFT的好方法.     

薄板冷轧过程中宽展的变化规律及其影响因素

基于金属流动原理,采用显式动力学有限元软件ANSYS/LS-DYNA模拟薄板轧制过程,研究轧制力、摩擦系数、压下率对轧件宽展变化的影响。结果表明,摩擦系数越大,轧件宽展也越大;轧件的最大宽展随着轧制力的增加而增大,轧制力对轧件后端部分宽展影响程度较大;压下率增大,轧件宽展随之增大,轧件各部分宽展的不均匀程度也在增加。     

拟协调等腰梯形薄板弯曲元和薄壳元

用拟协调方法推导了正交各向异性等腰梯形薄板弯曲元和薄平面壳元的显式刚度阵。计算结果表明，这种单元由于不需要进行数值积分，收敛愉、精度好，具有良好的适用性和可靠性。该单元已装配到ＤＤＪＴＪＱ程序系统中。     

石墨烯与掺N石墨烯对甲酸盐电氧化催化剂Pt和Pd抗毒性的提升研究

为研究载体对甲酸盐电氧化催化剂抗毒性的促进作用,将商用催化剂Pt/C和Pd/C分别与石墨烯(GNs)及掺N石墨烯(NGNs)超声混合后涂制电极,通过循环伏安法(CV)及计时电流法(CA)比较了混合GNs及NGNs对催化剂抗毒性的影响.结果表明,加入GNs和NGNs均可提高Pt/C与Pd/C的抗毒性,其中NGNs提升作用更显著.该研究表明,石墨烯类材料改善催化剂抗毒性具有普适意义.     

浅谈瘦客户端的网络技术

面对网络快速发展以及IT技术的日益复杂,越来越多的用户开始关注单位自身IT环境的安全性和可管理性。随着各单位信息化架构的日益扩充和完善,单位的信息化架构也面临着日益增加的技术与商务的风险和挑战。瘦客户端成为了基于服务器的计算解决方案的主要组成部分。     

热压碳化硼的热导率和膨胀系数

用激光闪烁法测定碳化硼的导热系数,用DF 1500膨胀仪测定热膨胀系数,研究了其热导率与温度、孔隙度和晶粒度的关系.研究结果表明:碳化硼热导率与温度的关系可表示为1/λ=2+0.0055t或1/λ=(6.28t+1840)×105;热导率与孔隙度的关系可表示为λ=λs(1-θ)/(2+2.2θ)或λ=λs(1-1.5θ);当θ=0.08,且在室温时,碳化硼平均热膨胀系数为4.4×10-6/K,从而可保证该材料在快中子反应堆中安全使用.     

Preparation and performance of novel LLTO thin film electrolytes for thin film lithium batteries

We prepared a series of lithium lanthanum titanate(LLTO) thin film electrolytes by radio frequency(RF) magnetron sputtering using LLTO targets in a N2 atmosphere.We also deposited the LLTO thin films in an Ar atmosphere under a same condition as references for comparison.The microstructure morphology and the composition of the thin films were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS),respectively.Results show that the thin film has an amorphous structure with a uniform surface and it is free of pinholes and cracks.Impedance measurements reveal that the ionic conductivity of the electrolytes is beneficial for all solid lithium batteries dependent on the lithium content at room temperature.We found that the amorphous LLTO thin film performs well and it has potential application in microbatteries for use in microelectronic devices.     

纳米Pt/Graphene复合电极的制备及对甲醇电催化性能的影响

采用一步还原法制备直接甲醇燃料电池纳米Pt/graphene (Pt/G)阳极. XRD和SEM表征表明Pt纳米均匀分散于石墨烯表面.循环伏安和计时电流的电化学测定结果表明:复合纳米Pt/G的催化活性和稳定性优于纯铂;采用计时电量法测定298 K时甲醇在硫酸溶液中扩散系数为1.37×10-9 cm2·s-1,以及在不同阶跃电位下甲醇催化氧化反应速率常数k_f.      

Preparation and Application of Water Dispersible Graphene as Antistatic Agent for SMS Nonwovens

In this paper, glucose was used as a green reducing agent and a capping reagent in the synthesis of water dispersible graphene, while using exfoliated graphite oxide （GO） as the precursor with the modified Hummers method. Characterizations of the graphene were conducted by UV-visihle absorption spectroscopy and X-ray diffraction （XRD）. Then the spunlaid-melthlowing-spuulaid （SMS） nonwovens were treated with the graphene solution via pad-dry-cure process. The surface and the antistatic property of the obtained nonwovens were tested. The results showed that O. 1 mg/mL graphene solution exhibited good stability in water. When treated with this solution, the graphene could be evenly dispersed on SMS nonwovens and the nonwovens had an excellent antistatic performance and a high relatively antistatic durability.