共查询到19条相似文献,搜索用时 149 毫秒
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以C-V测量、击穿电压测量并结合逐层腐蚀技术,对GaAs外延多层结构的剖面分布进行了测量,获得了GaAs(100)晶片在不同温度下的H_2SO_4-H_2O溶液中的腐蚀速度数据。结果表明,当H_2SO_4:H_2O_2:H_2O=9:1:1时,对n=1.10 ̄(14)~1.10 ̄(18)cm ̄-3的GaAs(100)晶片,20℃时的腐蚀速度为v=0.3~0.9μm/min.作者认为,这一配方对GaAs(100)多层结构是一个最为理想的减薄腐蚀剂。 相似文献
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用新前体分子束外延立方GaN日本筑波大学科研人员应用单分子联氨(MMHy)为新型氮源,首次成功地制备了立方GaN(c-GaN)外延层。实验仪器为传统的MOMBE设备,基底是以H2SO4:H2O2:H2O=5:1:1腐蚀液刻蚀的SI-GaAs(100)... 相似文献
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电渣熔铸900mm冷交换器顶盖孟军陈崇峰(武汉重型铸锻厂)(武汉冶金科技大学)ESRCASTINGPROCESSFORTHE900mmTOP┐COVEROFCOLDEXCHANGERMengJun(WuhanHeavyProductsCastan... 相似文献
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刚玉碳化硅砖在硅铁电炉出铁口上的应用把多华(西北铁合金厂)UTILIZATIONOFBRICKOFALUMINA-CARBOFRAXINTAPPINGHOLEOFFERROSILICONFURNACE¥BaDuoHua(North-Westferro... 相似文献
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抓住机遇大力提高连铸比推动钢铁工业发展刘淇(冶金工业部)GRA8PTHBOPPORTUNITY,INCREASETHECONTINUOUSCASTINGRATEANDPROMOTETHEDEVBLOPMBNTOFIRONANDSTEELINDUsTR... 相似文献
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GSMBE法ZnSe外延层中的晶体缺陷日本三菱电子公司最近研究了气态源分子束外延ZnSe膜初始阶段的晶体缺陷。实验以金属锌和H2Se为源,在具有(4×8)Ga稳定表面的(100)GaAs缓冲层上生长ZnSe。用反射高能电子衍射(PHEED)原位监测了... 相似文献
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《粉末冶金学》2013,56(2):53-59
AbstractThe examination of P/M microstructures by automated image analysis requires a reproducible high level of surface finish from the section of the specimen under investigation. The preparation of mechanically polished sections involves a number of procedures each susceptible to variation. The effect of variations taken together can be large, resulting in erroneous information. A quantitative assessment of each procedure for polishing specimens from an iron P/M system has been conducted using automated polishing machines. The porosity of sintered iron compacts was measured using an automated image analysing computer. The ‘measured’ porosities were compared with the ‘true’ bulk porosity in each case to assess the variation due to each polishing parameter. Although a universal set of polishing conditions cannot be given, the results enable a set of optimized polishing conditions to be derived. 相似文献
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The etching technique using Ce is a convenient and fast method for polishing and shaping diamond films. In this study, the influence of polishing parameters such as polishing temperature and time on the surface crystallinity and phase composition of diamond films was thoroughly investigated via the analysis of Raman spectra such as FWHM and ID/IG. Moreover, the issue on the graphitization of diamond after polishing with Ce was further researched through the detailed study of the depth distribution of Raman data including FWHM and ID/IG, and a result completely different from the hot-iron metal polished ones was obtained. The results showed that polished diamond films had considerably higher diamond content than those before polishing, and not a bit of graphitization was found in the polished ones, owing to a higher solubility of carbon in rare earth metal Ce than that in transition metals, and the original crystallinity of the films polished with Ce did not deteriorate. 相似文献
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表征了打磨态和机械抛光态316LN不锈钢表面的粗糙度、表面残余应变和表面电子功函数的分布,并研究了打磨态和机械抛光态样品在硼酸盐溶液中电化学腐蚀行为的差异.与机械抛光态316LN不锈钢相比,打磨处理后样品表面较为粗糙,且表面的微观残余应变较大,近表面产生约50μm的加工硬化层.表面粗糙度和微观应变的增加引起打磨态表面电化学活性的增大,从而促进316LN不锈钢在硼酸盐溶液中腐蚀.机械抛光处理降低了表面钝化膜的载流子密度(供体和受体),并增大了钝化膜的阻抗,提高了钝化膜的致密性和保护性,能够有效抑制金属的进一步腐蚀. 相似文献
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为了研究制样方法对钢铁材料纳米压痕试验结果的影响,选取单相、多相、低碳、中碳和高碳等不同类型的钢种,分别进行了纳米压痕样品制备参数的探索。利用机械磨抛和电解抛光设备进行了样品表面抛光处理,比较了氧化物机械抛光及不同参数的电解抛光对样品表面状态的影响,通过真彩共聚焦扫描显微镜定量测定了样品表面粗糙度。随后,为检验样品制备的效果,利用纳米压痕仪分别测试了两种抛光方式得到的不同组织的纳米硬度和弹性模量。结果表明,氧化物机械抛光适合制备单相且试验压入深度超过500nm的样品;电解抛光能有效避免表面硬化层,在参数适当的条件下,既可以满足测试标准的要求,又可以进行多相区分,但是,电解参数不当时会导致组织假象,严重影响测试结果的准确性。同时,对制样效果的评价应考虑试验曲线的稳定性而不仅仅注重抛光样品的平均表面粗糙度。最后,给出了适用于低碳钢W1300、中碳钢SWRCH35K和高碳钢SWRH82B的电解抛光参数,可为类似钢铁材料纳米压痕测试样品的制备提供参考和借鉴。 相似文献