共查询到16条相似文献,搜索用时 93 毫秒
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KDP晶体二倍频晶面纳米压痕实验研究 总被引:1,自引:1,他引:0
The nanohardness is from 1.44 to 2.61 GPa,the Vickers hardness is from 127 to 252 Vickers,and elastic modulus is from 52 to 123 GPa by the nanoindentation experiments on the doubler plane of KDP crystal. An indentation size effect is observed on the doubler plane in the test as the nanohardness and elastic modulus decreases with the increase of the maximum load.Slippage is identified as the major mode of plastic deformation, and pop-in events are attributed to the initiation of slippage.And the variation of unloading curve end is the result of stick effects between the indenter and the contact surface.The depth of the elastic deformation,which is between 40 and 75 nm,is responsible for the elastic deformation.The doubler plane of KDP crystal has anisotropy,and the relative anisotropy of nanohardness is 8.2%and the relative anisotropy of elastic modulus is 8.0%. 相似文献
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单晶锗飞切加工时,观察切屑形成较为困难.针对该问题,文中采用了一种无网格仿真方法(SPH法),通过建立单晶锗(111)晶面微切削仿真模型,研究塑性去除时,切削深度、切削速度对切削力及切屑形成的影响.结果表明,在切削速度为4μm·μs-1,切削深度分别为0.5μm、1μm、2μm、5μm时,切向力及法向力都出现逐渐增大然... 相似文献
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GaN在Si(001)上的ECR等离子体增强MOCVD直接生长研究 总被引:3,自引:0,他引:3
研究了用电子回旋共振(ECR)等离子体增强金属有机物化学气相沉积(PEMOCVD)技术在Si(001)衬底上,低温(620~720℃)下GaN薄膜的直接外延生长及晶相结构.高分辨透射电镜(HRTEM)和X射线衍射(XRD)结果表明:在Si(001)衬底上外延出了高度c轴取向纤锌矿结构的GaN膜,但在GaN/Si(001)界面处自然形成了一层非晶层,其两个表面平坦而陡峭,厚度均匀(≈2nm).分析认为,在初始成核阶段N与Si之间反应所产生的这层SixNy非晶层使GaN的β相没有形成.XRD和原子力显微镜(AFM)结果表明,衬底表面的原位氢等离子体清洗,GaN初始成核及后续生长条件对GaN膜的晶体质量非常重要. 相似文献
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研究了用电子回旋共振(ECR)等离子体增强金属有机物化学气相沉积(PEMOCVD)技术在Si(001)衬底上,低温(620~720℃)下GaN薄膜的直接外延生长及晶相结构.高分辨透射电镜(HRTEM)和X射线衍射(XRD)结果表明:在Si(001)衬底上外延出了高度c轴取向纤锌矿结构的GaN膜,但在GaN/Si(001)界面处自然形成了一层非晶层,其两个表面平坦而陡峭,厚度均匀(≈2nm).分析认为,在初始成核阶段N与Si之间反应所产生的这层SixNy非晶层使GaN的β相没有形成.XRD和原子力显微镜(AFM)结果表明,衬底表面的原位氢等离子体清洗,GaN初始成核及后续生长条件对GaN膜的晶体质量非常重要. 相似文献
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高压对半导体材料β-FeSi2带隙和光学性质具有很好的调节作用。在本工作中,我们利用密度泛函理论研究了高压对具有Si缺陷结构的β-FeSi2 (100)/Si(001) 界面光学吸收行为的影响。随着压强的增大,光学吸收峰首先减小到一个最小值,然后才慢慢的增大。电子轨道分析表明:电子从价带的最高占据态到导带的最低非占据态的跃迁过程主要发生在界面区域的Fe原子轨道。结构分析表明:这种新奇光吸收行为依赖于施加在β-FeSi2 (100)界面区域的压力,Si(001) 结构可以部分的抵消施加在β-FeSi2 (100) 界面区域的压力,从而造成光吸收峰的下移。但是,当施加的压力足够大时,这种抵消作用开始减弱,从而造成光学吸收峰缓慢的上移。本研究表明压力可以有效的修饰其光学吸收行为。 相似文献
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用最近邻及次邻中心相互作用势讨论了清洁的Mo(001)表面声子。作为初步近似,用质量亏损模型讨论了不同吸附原子质量对表面声子的影响。 相似文献
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研究了SiC衬底(0001)面和(000-1)面不同的CMP抛光特性.分别采用pH值为10.38和1.11的改性硅溶胶抛光液对SiC衬底的(0001)Si面和(000-1)C面进行对比抛光实验.使用精密天平测量晶片抛光前后的质量,计算出CMP抛光工艺的材料去除速率.并使用强光灯、微分干涉显微镜和原子力显微镜检测晶片表面质量.发现采用酸性抛光液和碱性抛光液进行抛光,均有Vc>Vsi;而对于(0001) Si面,有Vsi 酸>Vsi碱;对于(000-1)C面,有Vc酸>Vc碱.该结论对于探索最佳碳化硅的CMP抛光工艺具有较高价值. 相似文献
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用快速率(1.0ML/s)生长MBE InAs/GaAs(001)量子点。原子力显微镜观察结果表明,在量子点体系形成的较早阶段,量子点密度N(θ)随InAs沉积量θ的变化符合自然指数形式N(θ)∝ek(θ-θc),这与以前在慢速生长(≤0.1ML/s)条件下出现的标度规律N(θ)∝(θ-θc)α明显不同。另外,在N(θ)随θ增加的过程中,快速率生长量子点的高度分布没有经历量子点平均高度随沉积量θ逐渐增加的过程。这些实验观察说明,以原子在生长表面作扩散运动为基础的生长动力学理论至少是不全面的,不适用于解释InAs量子点的形成。这些观察和讨论说明,即使在1.0ML/s的快速率生长条件下,量子点密度也可以通过InAs沉积量有效地控制在1.0×108cm-2以下,实现低密度InAs量子点体系的制备。 相似文献
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K. G. Eyink L. Grazulis J. C. Reber J. D. Busbee 《Journal of Electronic Materials》2002,31(10):1112-1116
A single-point diamond machine fabricated patterns with a series of equispaced lines in an area of nominally 10 μm × 10 μm.
On a single GaAs wafer, patterns having 80, 100, 120, and 140 lines were machined. Sample patterns were formed with 5-mg and
7-mg loads. Atomic force microscopy (AFM) characterized the surface morphology and depth of cut of these patterns as a function
of load and indicated a consistent depth of cut for a given load. Subsurface damage in these layers was compared using the
ratio of the TO to the LO phonon peak intensities in the μ-Raman spectra with and without annealing. 相似文献
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T. Lien Tran Fariba Hatami W. Ted Masselink Vas P. Kunets G.J. Salamo 《Journal of Electronic Materials》2008,37(12):1799-1805
We describe the epitaxial growth of InSb films on both Si (001) and GaAs (100) substrates using molecular-beam epitaxy and
discuss the structural and electrical properties of the resulting films. The complete 2 μm InSb films on GaAs (001) were grown
at temperatures between 340°C and 420°C and with an Sb/In flux ratio of approximately 5 and a growth rate of 0.2 nm/s. The
films were characterized in terms of background electron concentration, mobility, and x-ray rocking curve width. Our best
results were for a growth temperature of 350°C, resulting in room-temperature mobility of 41,000 cm2/V s. For the growth of InSb on Si, vicinal Si(001) substrates offcut by 4° toward (110) were used. We investigated growth
temperatures between 340°C and 430°C for growth on Si(001). In contrast to growth on GaAs, the best results were achieved
at the high end of the range of T
S = C, resulting in a mobility of 26,100 cm2/V s for a 2 μm film. We also studied the growth and properties of InSb:Mn films on GaAs with Mn content below 1%. Our results
showed the presence of ferromagnetic ordering in the samples, opening a new direction in the diluted magnetic semiconductors. 相似文献