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1.
利用金属蒸气真空弧 (MEVVA)离子源将稀土元素Er离子掺杂到富硅热氧化SiO2 /Si薄膜中。卢瑟福背散射 (RBS)和X 射线电子能谱仪 (XPS)分析表明 ,Er浓度可达原子百分数 (x)~ 10 ,即Er的原子体浓度为~ 10 2 1·cm-3 。XPS研究发现 ,随着Si注量增大 ,退火态样品表面硅含量增多 ,热氧化硅含量减少。反射式高能电子衍射 (RHEED)和原子灵敏度因子法 (AFM)研究表明 ,样品表面没有大量Er析出或铒硅化物形成 ,退火后表层中Si外延再生长、有针状微晶硅颗粒形成。在 77K及室温下 ,研究了Er掺杂富硅热氧化SiO2 /Si薄膜的近红外区 1 5 4μm附近光致发光光谱  相似文献   
2.
杨建华  张通和 《中国物理》2005,14(3):556-559
H13 die steel was implanted with tungsten using a metal vapour vacuum arc (MEVVA) ion source. When the pulsed beam current density of tungsten ions increased to 6mA?cm-2, some voids appeared in the high voltage electron microscope (HVEM) micrograph, which would disappear at an annealing temperature of 600℃. HVEM and x-ray diffraction were used for observing the phase structure of the annealed and un-annealed H13 steel after the steel was implanted. Results of wear and hardness tests indicated that whether the voids appear significantly influences the hardness and wear of H13 steel. Reasons for the formation of voids and the relation between the surface mechanical property and voids are discussed in terms of collision theory.  相似文献   
3.
Molybdenum ions are implanted into aluminium with high ion flux and high dose at elevated temperatures of 200℃, 400℃ and 500℃. Due to the high temperature and high flux of vacancies and interstitial atoms, the atom diffusion and chemical effects are enhanced during the ion implantation. The effects increase with increasing ion flux and dose, so that new phase formation and phase transition emerge noticeably. X-ray diffraction analysis shows that when the aluminium is implanted with Mo ions at a low ion flux (25μA/cm2), the Al5Mo alloy is formed. The atomic ratio of Mo/Al of the Al5Mo phase is close to 20%. When the aluminium is implanted with Mo ions at a high ion flux (50μA/cm2), the phase transition from Al5Mo to Al12Mo appears, and the latter is dominant, which is determined to be the final phase. The ratio of Mo/Al in Al12Mo is 7.7%. Rutherford backscattering spectroscopy indicates also that the Mo/Al atom ratio is ~7% to ~8% in Mo-implanted aluminium. The atomic ratios of the constituents in Al5Mo and Al12Mo are of stoichiometric composition for these alloys. The thicknesses of the Al12Mo alloy layers for Mo-implanted Al with ion doses of 3×1017/cm2 and 1×1018/cm2 are 550nm and 2000nm, respectively. The pitting corrosion potential Vp increases obviously. It is clear that due to the formation of Al12Mo alloy layer, the pitting corrosion resistance is enhanced.  相似文献   
4.
综合评述了本课题组在金属离子注入钢强化机理、表面摩擦学、抗磨损特性、离子注入表面热化学效应、硅化物合成、表面抗氧化和抗腐蚀研究中所取得的新的实验结果. A review of our research work is given in this paper. It is about strengthening mechanism; surface trobology; resistance in wear, oxidation and corrosion; thermal atom chemistry in steel during ion implantation; silicides synthesis.  相似文献   
5.
采用强流金属蒸汽真空弧(MEVVA)离子源注入机,先将Si大束流注入热氧化SiO2/单晶硅,直接形成镶嵌在SiO2中的纳米晶Si,再小束流注入Er。Er离子在掺杂层中的浓度可达10^21cm^-3量级,大大地提高了作为孤立发光中心的Er^3 浓度。在77K和室温下,观察到了Er^3 的1.54цm特征发射。  相似文献   
6.
一、引 言 采用高功率的激光束辐照离子注入硅样品能够获得比热退火优越的电特性.利用离子束背散射分析技术,能够进行定量的非破坏性测量.一般说来,测量本身不会带来负效应[1].本工作采用离子束背散射技术和电特性测量,对注有砷离子的硅样品的退火行为进行了比较和分析.发现用大剂量(1×1016/cm2)注入的样品在1000℃下,经20分钟退火后,能够获得一个接近于理想的突变结.而红宝石脉冲激光退火,无论从注入损伤的恢复还是从载流子浓度方面来看,都比热迟火优越. 二、实验方法和实验条件的选择 实验样品选用P-型(111)硅单晶片,电阻率p=7-15Ω·cm…  相似文献   
7.
掺铒硅基材料发光的新途径   总被引:5,自引:1,他引:4       下载免费PDF全文
关键词:  相似文献   
8.
先进的离子束技术和材料改性   总被引:1,自引:0,他引:1  
张通和 《物理实验》2001,21(4):3-7,10
介绍了离子束形成、材料改性的科学意义及离子束在国民经济和国防中的地位和应用.  相似文献   
9.
用掩蔽注入法研究钛注入H13钢的耐磨性   总被引:2,自引:0,他引:2       下载免费PDF全文
杨建华  张通和 《物理学报》2004,53(11):3823-3828
采用由金属蒸汽真空弧离子源引出的强束流钛、碳离子对H13钢进行表面改性研究.钛和碳离子注入剂量分别为3×1017和1×1017cm-2,引出电压分别为48和30kV,平均束流密度分别为47和20μA·cm-2.为了保持相同的摩擦磨损实验条件,注 入过程中采用掩蔽注入技术.摩擦磨损实验结果表明,钛离子注入H13钢提高了其耐磨性,并大幅度降低其摩擦系数.利用卢瑟福背散射谱测量了离子注入表面的成分,并采用逐层递推 法得出了钛在H13钢中的浓度深度分布,借助掠面x射线衍射考察了注入表面的相结构. 关键词: 钛离子注入 金属蒸汽真空弧 卢瑟福背散射 掠面x射线衍射  相似文献   
10.
The fractal and multi-fractal patterns of metal atoms are observed in the surface layer and cross section of a metal ion implanted polymer using TEM and SEM for the first time. The surface structure in the metal ion implanted polyethylene terephthalane (PET) is the random fractal. Certain average quantities of the random geometric patterns contain self-similarity. Some growth origins appeared in the fractal pattern which has a dimension of 1.67. The network structure of the fractal patterns is formed in cross section, having a fractal dimension of 1.87. So it can be seen that the fractal pattern is three-dimensional space fractal. We also find the collision cascade fractal in the cross section of implanted nylon, which is similar to the collision cascade pattern in transverse view calculated by the TRIM computer program. Finally, the mechanism for the formation and growth of the fractal patterns during ion implantation is discussed.  相似文献   
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