共查询到18条相似文献,搜索用时 406 毫秒
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采用磁控溅射技术在Si衬底上以350?C沉积14 nm的非晶Ge薄膜,通过退火改变系统生长热能,实现了低维Ge/Si点的生长.利用原子力显微镜(AFM)和拉曼(Raman)光谱所获得的形貌和声子振动信息,对Ge点的形成机理和演变规律进行了研究.实验结果表明:在675?C退火30 min后,非晶Ge薄膜转变为密度高达8.5×109cm-2的Ge点.通过Ostwald熟化理论、表面扩散模型和对激活能的计算,很好地解释了退火过程中,Ge原子在Si表面迁移、最终形成纳米点的行为.研究结果表明用高速沉积磁控溅射配合热退火制备Ge/Si纳米点的方法,可为自组织量子点生长实验提供一定的理论支撑. 相似文献
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通过二次离子质谱仪(SIMS)研究了Mo在Zr57Nb5Cu15.4Ni12.6Al10非晶合金中的扩散,并计算出其扩散激活能Q和前置系数D0分别为1.95 eV和1.13×10-5 m2s-1.根据Stokes-Einstern关系式研究了玻璃转变温度以下593-673 K之间Zr57Nb5Cu15.4Ni12.6Al10非晶合金的黏滞特性,得到的黏滞系数从593 K的1.07×1010Poise降到673 K的1.42×108 Poise. 相似文献
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采用X射线衍射(XRD),杨氏模量测量方法研究了非晶态Fe73.5Cu1Nb3Si13.5B9合金500℃等温晶化时,纳米α-Fe(Si)晶相的平均晶粒尺寸(d),晶化体积分数(Vc),杨氏模量(E)随保温时间(t)的变化.d-t关系具有阶梯式长大特征,而E-t关系则呈现相应的周期性变化.分别计算了纳米α-Fe(Si)晶生长前沿非晶区的化学成分以及晶间非晶区平衡化学成分.由Fick扩散方程计算晶间非晶区成分均匀化的时间,与纳米α-Fe(Si)阶梯式长大周期相当.E-t关系的振荡性变化可能是由扩散控制的纳米α-Fe(Si)晶相的阶梯式长大与晶间非晶区周期性弛豫引起的. 相似文献
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以微区Raman散射、X射线光电子能谱和红外吸收对等离子体增强化学气相沉积(PECVD)法制备的氢化非晶硅氧(a-Si:O:H)薄膜微结构及其退火行为进行了细致研究。结果表明a-Si:O:H薄膜具有明显的相分离结构,富Si相镶嵌于富O相之中,其中富Si相为非氢化四面体结构形式的非晶硅(a-Si),富O相为Si,O,H三种原子随机键合形成的SiOx:H(x≈1.35)。经1150℃高温退火,薄膜中的H全部释出;SiOx:H(x≈1.35)介质在析出部分Si原子的同时发生结构相变,形成稳定的SiO2和SiOx(x≈0.64);在析出的Si原子参与下,薄膜中a-Si颗粒固相晶化的成核和生长过程得以进行,形成纳米晶硅(nc-Si),研究发现此时的薄膜具有典型的壳层结构,在nc-Si颗粒表面和外围SiO2介质之间存在着纳米厚度的SiOx(x≈0.64)中间相。 相似文献
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以微区Raman散射、X射线光电子能谱和红外吸收对等离子体增强化学气相沉积(PECVD)法制备的氢化非晶硅氧(a-Si∶O∶H)薄膜微结构及其退火行为进行了细致研究.结果表明a-Si∶O∶H薄膜具有明显的相分离结构,富Si相镶嵌于富O相之中,其中富Si相为非氢化四面体结构形式的非晶硅(a-Si),富O相为Si,O,H三种原子随机键合形成的SiOx∶H(x≈1.35).经1150℃高温退火,薄膜中的H全部释出;SiOx∶H(x≈1.35)介质在析出部分Si原子的同 相似文献
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a-SiCx:H/nc-Si:H多层薄膜的室温时间分辨光致可见发光 总被引:1,自引:1,他引:0
在等离子体增强化学气相沉积(PECVD)系统中,通过控制进入反应室的气体种类逐层沉积非晶SiCx:H(a-SiCx:H)和非晶Si:H(a-Si:H)薄膜,然后经过高温热退火处理,成功制备了晶化纳米a-SiCx:H/nc-Si:H(多晶SiC和纳米Si)多层薄膜。利用截面透射电子显微镜技术分析了a-SiCx:H/nc-Si:H多层薄膜的结构特性。通过对晶化样品的时间分辨光致发光谱的研究,结果表明:随着退火温度的升高,发光峰位置开始出现一些红移现象:当退火温度为900℃时,样品的发光强度和发光衰减时间分别达到最大值和最小值;随着退火温度的继续升高,发光峰位置又开始出现蓝移现象。由此探讨纳米a-SiCx:H/nc-Si:H多层薄膜的发光特性和发光机理。 相似文献
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A. E. Dolbak B. Z. Ol’shanetskii S. A. Tiis R. A. Zhachuk 《Physics of the Solid State》1999,41(8):1364-1368
The effect of the coadsorption of Co and Ni on an Si(111) surface structure and on the diffusion of adsorbed atoms is investigated
by low-energy electron diffraction and Auger electron spectroscopy. It is established that surface structures similar to those
formed with the adsorption of Co alone are formed with the Ni and Co coadsorption on an Si(111) surface. It is found that
the contribution of surface diffusion to the transport of Ni atoms is sharply higher on an Si(111) surface with submonolayer
Co concentrations in the temperature range 500–750 °C than for a pure surface, where the main mechanism of Ni transport along
the surface is diffusion of Ni atoms through the bulk of Si.
Fiz. Tverd. Tela (St. Petersburg) 41, 1489–1494 (August 1999) 相似文献
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Temperature and substrate dependence of structure and growth mechanism of carbon nanofiber 总被引:1,自引:0,他引:1
The carbon nanofibers were grown on Ni/Si and Ni/Ti/Si substrates in 1 atm CH4 atmosphere at 640 °C and 700 °C by thermal chemical vapor deposition method. The carbon nanofibers were characterized by field emission scanning electron microscopy, transmission electron microscopy, and Raman spectrometry for morphology, microstructure, and crystallinity. The electron emission property of carbon nanofibers was also investigated by current-voltage (I-V) measurement. The results showed that the solid amorphous carbon nanofibers could be grown on Ni/Si substrate at 640 °C through tip growth mechanism, the carbon nanotubes could be grown on Ni/Si substrate at 700 °C through tip growth mechanism, and the carbon nanotubes could be grown on Ni/Ti/Si substrate at 700 °C through root growth mechanism. 相似文献
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In this study, an electroplating method to deposited Ni, crystalline NiW(c-NiW), amorphous NiW (a-NiW) films on P-type Si(1 0 0) were used to form Ni-silicide (NiSi) films. After annealed at various temperatures, sheet resistance of Ni/Cu, c-NiW/Cu and a-NiW/Cu was measured to observe the performance of those diffusion barrier layers. With W added in the barrier layer, the barrier performance was improved. The results of XRD and resistance measurement of the stacked Si/Ni(W)/Cu films reveal that Cu atom could diffuse through Ni barrier layer at 450 °C, could diffuse through c-NiW at 550 °C, but could hardly diffuse through a-NiW barrier layer. c-NiW layer has a better barrier performance than Ni layer, meanwhile the resistance is lower than a-NiW layer. 相似文献
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The diffusion of Ni on a Si (111) surface is investigated by LEED and Auger electron spectroscopy. It is found that, in contrast
to the process on the initially clean Si (111)−7×7 surface, on Si (111) surfaces with submonolayer Co coverages the nature
of the Ni transport mechanism changes at a temperature of about 750 °C, and the Ni surface diffusion coefficients increase
sharply below this temperature.
Pis’ma Zh. éksp. Teor. Fiz. 66, No. 9, 611–614 (10 November 1997) 相似文献
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Ki-Hong Lee Charles Lofton Won-Seon Seo Myung-Hyun Lee 《Solid State Communications》2004,131(11):687-692
Photoluminescence characteristics of amorphous silica nanowires (a-SiONWs) grown on TiN/Ni/Si and TiN/Ni/SiO2 substrates have been studied. A-SiONWs grown on TiN/Ni/Si substrates show a Si-rich composition compared to those grown from TiN/Ni/SiO2/Si. The emission characteristics of the nanowires were found to depend on the type of substrate. By annealing the a-SiONWs grown on TiN/Ni/Si in air, emission bands shift from blue to green bands. It is likely that silicon to oxygen ratio is an important factor in deciding the types of defects and emission bands of amorphous silica nanowires. 相似文献
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Role of buried ultra thin interlayer silicide on the growth of Ni film on Si(100) substrate 总被引:1,自引:0,他引:1
D.K. Sarkar M. Falke H. Giesler S. Teichert G. Beddies H.-J. Hinneberg 《Applied Physics A: Materials Science & Processing》2000,70(6):681-684
The presence of a buried, ultra-thin amorphous interlayer in the interface of room temperature deposited Ni film with a crystalline
Si(100) substrate has been observed using cross sectional transmission electron microscopy (XTEM). The electron density of
the interlayer silicide is found to be 2.02 e/?3 by specular X-ray reflectivity (XRR) measurements. X-ray diffraction (XRD) is used to investigate the growth of deposited
Ni film on the buried ultra-thin silicide layer. The Ni film is found to be highly textured in an Ni(111) plane. The enthalpy
of formation of the Ni/Si system is calculated using Miedema’s model to explain the role of amorphous interlayer silicide
on the growth of textured Ni film. The local temperature of the interlayer silicide is calculated using enthalpy of formation
and the average heat capacity of Ni and Si. The local temperature is around 1042 K if the interlayer compound is Ni3Si and the local temperature is 1389 K if the interlayer compound is Ni2Si. The surface mobility of the further deposited Ni atoms is enhanced due to the local temperature rise of the amorphous
interlayer and produced highly textured Ni film.
Received: 2 March 2000 / Accepted: 28 March 2000 / Published online: 11 May 2000 相似文献
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J. J. Suñol 《哲学杂志》2013,93(20):2323-2342
Progress in the ball milling amorphization of elemental powders with the overall composition Fe40Ni40P20 ? xSix (X = 6, 10 and 14) and thermally induced crystallization of obtained alloys were characterized by differential scanning calorimetry, X-ray diffraction and transmission Mössbauer spectroscopy (TMS). Diffusion of Si into Fe and Ni alloys promotes the formation of the amorphous phase, via previous formation of (Fe, Ni) phosphides. After milling for 32–64 h, most of the powders are amorphous but bcc Fe(Si) crystallites remain (about 5% in volume). TMS results indicate that homogenization of the amorphous phase occurs by interdiffusion of Ni and Fe in Fe(Si,P)-rich and Ni(Si,P)-rich zones respectively. Annealing induces structural relaxation of stresses induced by milling, growth of bcc Fe(Si) crystallites, precipitation of bcc Fe(Si) and fcc Ni–Fe, and minor phases of Ni-rich silicides and (Fe, Ni) phosphides. The main ferromagnetic phase is bcc Fe(Si) for Fe40Ni40P10Si10 powders obtained after milling for 32 h. However, it is fcc Fe–Ni for the same alloy after milling for 64 h. In the later powders, as well as for alloys with x = 6 and 14 milled for 32 h, the fcc Fe–Ni shows the Invar magnetic collapse. 相似文献