共查询到17条相似文献,搜索用时 258 毫秒
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采用熔渗法研究了烧结压力、烧结温度以及烧结时间对金属添加剂金刚石烧结体性能的影响;在1 400 ℃、5.8 GPa、12 min的烧结条件下,烧结出磨耗比为285×103、金刚石颗粒未出现异常长大的金刚石烧结体;分析了烧结方法对烧结效果的影响。 相似文献
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利用石英的拉曼谱峰与温度和压力的关系,检验了在金刚石压腔中用方解石拉曼谱峰确定体系压力的可行性,并初步确定了在常温下方解石的拉曼谱峰与压力的关系。实验研究结果表明:在实验的压力范围内方解石稳定,且其1 085 cm-1 谱峰约为石英464 cm-1谱峰的3倍强度,因此非常适合作为热液金刚石压腔的压力标定物。在温度26 ℃、压力0.1~800 MPa条件下,方解石的拉曼谱峰(1 085 cm-1)随着压力的增加,呈线形增大,其关系式为:p(MPa)=192×(νp-1 085)-21.8,1 085 cm-1<νp<1 090 cm-1。 相似文献
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SiC1-xGex/SiC 异质结光电二极管特性的研究 总被引:5,自引:5,他引:0
使用二维器件模拟软件Medici, 对SiC1-xGex/SiC异质结的光电特性进行了模拟.设计了N型重掺杂SiC层的厚度为1 μm, P型轻掺杂SiC1-xGex层厚为0.4 μm, 二者之间形成突变异质结.在反向偏压3 V、光强度为 0.23 W/cm2的条件下, p-n+ SiC0.8Ge0.2/SiC和p-n+ SiC0.7Ge0.3/SiC敏感波长λ分别可以达到0.64 μm和0.7 μm, 光电流分别为7.765×10-7 A/μm和7.438×10-7 A/μm; 为了进一步提高SiC1-xGex/SiC 异质结的光电流, 我们把p-n+两层结构改进为p-i-n三层结构.在同样的偏压、光照条件下, p-i-n SiC0.8Ge0.2/SiC和p-i-n SiC0.7Ge0.3/SiC的光电流分别达到1.6734×10-6 A/μm和1.844×10-6 A/μm. 相似文献
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建立起一套侧向阴影照相的光学系统,利用可见光作为探测光,在状态方程实验中对靶的飞行速度进行探测。在天光KrF准分子激光装置上进行激光打靶实验,激光波长为248.4 nm。在激光功率密度为8.3×1011 W/cm2的条件下,测得50 μm厚铝靶的飞行速度为3.28 km/s;在激光功率密度为4.7×101011 W/cm2的条件下,测得带100 μm厚烧蚀层的13 μm厚铝靶的飞行速度为2.52 km/s。最后进行了误差分析计算,实验中探测激光与靶表面偏离角度最大不会超过2.06°,偏离角对实验精度产生的影响可以被忽略。 相似文献
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Amorphous SiO2 thin films with about 400—500 nm in thickness were thermally grown on single crystalline silicon. These SiO2/Si samples were firstly implanted at room temperature (RT) with 100 keV carbon ions to 2.0×1017, 5.0×1017 or 1.2×1018 ions/cm2, then irradiated at RT by 853 MeV Pb ions to 5.0×1011, 1.0×1012, 2.0×1012 or 5.0×1012 ions/cm2, respectively. The variation of photoluminescence (PL) properties of these samples was analyzed at RT using a fluorescent spectroscopy. The obtained results showed that Pb-ion irradiations led to significant changes of the PL properties of the carbon ion implanted SiO2 films. For examples, 5.0×1012 Pb-ions/cm2 irradiation produced huge blue and green light-emitters in 2.0×1017 C-ions/cm2 implanted samples, which resulted in the appearance of two intense PL peaks at about 2.64 and 2.19 eV. For 5.0×1017 carbon-ions/cm2 implanted samples, 2.0×1012 Pb-ions/cm2 irradiation could induce the formation of a strong and wide violet band at about 2.90 eV, whereas 5.0×1012 Pb-ions/cm2 irradiation could create double peaks of light emissions at about 2.23 and 2.83 eV. There is no observable PL peak in the 1.2×1018 carbon-ions/cm2 implanted samples whether it was irradiated with Pb ions or not. All these results implied that special light emitters could be achieved by using proper ion implantation and irradiation conditions, and it will be very useful for the synthesis of new type of SiO2-based light-emission materials. 相似文献
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The 9 and 12MeV proton irradiations of the Chinese CMOS Image Sensor in the fluence range from 1×109 to 4×10×10cm-2 and 1×109 to 2×1012cm-2 have been carried out respectively. The color pictures and dark output images are captured, and the average brightness of dark output images is calculated. The anti-irradiation fluence thresholds for 9 and 12~MeV protons are about 4×1010 and 2×1012 cm-2, respectively. These can be explained by the change of the concentrations of irradiation-induced electron-hole pairs and vacancies in the various layers of CMOS image sensor calculated by the TRIM simulation program. 相似文献
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Single-crystalline Si (100) samples were implanted with 30 keV He2+ ions to doses ranging from 2.0×1016 to 2.0×1017ions /cm2 and subsequently thermally annealed at 800℃ for 30min. The morphological change of the samples with the increase of implantation dose was investigated using atomic force microscopy (AFM). It was found that oblate-shaped blisters with an average height around 4.0nm were found on the 2.0×1016 ions /cm2 implanted sample surface; spherical-shaped blisters with an average height around 10.0nm were found on the 5.0×1016 ions /cm2 implanted sample surface; strip-shaped and conical cracks were observed on the sample He-implanted to a dose of 1.0×1017 ions /cm2. Exfoliations occurred on the sample surface to a dose of 2.0×1017 ions /cm2. Mechanisms underlying the surface change were discussed. 相似文献
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Scintillation detectors based on LSO, CeF and PbWO are the main candidates for measuring γ-rays in a mixed γ/n pulsed radiation field with high intensity. An experiment using the Lissajous figure method to study the high fluence rate response behavior of three kinds of commonly used scintillators is introduced in this paper. The result shows that the fluence rate linear response limit of LSO and CeF is 1.9×1019 and 2.1×1018MeV/(cm2·s), respectively, and the PbWO scintillator still maintains linear response when the fluence rate of γ-ray is up to 2.0 × 1020 MeV/(cm2·s). 相似文献
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本文采用DAC(金刚石压砧高压腔)装置,对氧化镍进行了静水压、非静水压、电导率测量等系统高压实验,获取了氧化镍等温压缩、高压相变及电导率压力效应的新结果,并在实验数据的基础上,对其高压相变与电性及磁性变化关系及体弹性模量作了分析讨论。 相似文献
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Nitrogen-Doped Chemical Vapour Deposited Diamond: a New Material for Room-Temperature Solid State Maser 下载免费PDF全文
N. A. Poklonski N. M. Lapchuk A. V. Khomich吕反修 唐伟忠V. G. Ralchenko I. I. Wlasov M. V. Chukichev Sambuu Munkhtsetseg 《中国物理快报》2007,24(7):2088-2090
Electron spin resonance (ESR) in polycrystalline diamond films grown by dc arc-jet and microwave plasma chemical vapour deposition is studied. The films with nitrogen impurity concentration up to 8 × 10^18 cm^-3 are also characterized by Raman, cathodoluminescence and optical absorption spectra. The ESR signal from P1 centre with g-factor of 2.0024 (nitrogen impurity atom occupying C site in diamond lattice) is found to exhibit an inversion with increasing the microwave power in an H102 resonator. The spin inversion effect could be of interest for further consideration of N-doped diamonds as a medium for masers operated at room temperature. 相似文献
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V. M. Astashynski A. Ya. Leyvi K. A. Talala V. V. Uglov N. N. Cherenda A. P. Yalovets 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2013,7(5):1005-1012
The change in the surface relief of a steel-3 target (GOST 380) treated by compression plasma flows is experimentally studied. The energy density absorbed by the target varies in the range of 10–35 J/cm2 and the pulse duration is 100 μs. It is shown experimentally and numerically that the development of KelvinHelmholtz instability strongly affects the formation of the target surface treated with compression plasma flows: a large-scale wave-like relief with characteristic sizes of 200 × 1000 μm is formed on the target surface and, as a result, the roughness of the surface increases. However, the microrelief at the scale of individual elements is smoothed to a maximum roughness of about 0.5 μm. 相似文献
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Long-time chronoamperometry of TiS2 electrodes immersed in saturated LiClO4/DMF solution was employed to investigate the charge transport processes which govern the rate of Li+ intercalation in TiS2. The intercalation rate and hence, the current, appears to be controlled by the rate of Li+ diffusion within the TiS2. A model has been developed which predicts the current-time behavior under the control of Li+ solid state diffusion. The close agreement of this model with the experimental data allows the solid state diffusion coefficient and other transport parameters (such as effective electrode area) to be evaluated from the measured average grain boundary distance. Typical TiS2 grain boundary distances in the 3–10 μm range yield a geometric mean value of 1.3 × 10?9 cm2/s for the solid state diffusion coefficient; this is in close agreement with previously reported diffusivities as measured by NMR spin-lattice relaxation techniques. 相似文献
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In-situ high pressure Raman spectra and electrical conductivity measurements of scheelite-structure compound PbMoO4 are presented. The Raman spectrum of PbMoO4 is determined up to 26.5 GPa on a powdered sample in a diamond anvil cell (DAC) under nonhydrostatic conditions. The PbMoO4 gradully experiences the trans- formation from the crystal to amorphous between 9.2 and 12.5 GPa. The crystal to amorphous transition may be due to the mechanical deformation and the crystalographic transformation. Furthermore, the electrical conductivity of PbMoO4 is in situ measured accurately using a microcircuit fabricated on a DAC based on the van der Pauw method. The results show that the electrical conductivity of PbMoO4 increases with increases of pressure and temperature. At 26.5 GPa, the electrical conductivity value of PbMoO4 at 295K is 1.93 - 10-4 S/cm, while it raises by one order of magnitude at 430K and reached 3.33 - 10-3 S/cm. However, at 430K, compared with the electrical conductivity value of PbMoO4 at 26.5 GPa, it drops by about two order magnitude at 7.4 GPa and achieves 2.81 × 10^-5 S/cm. This indicates that the effect of pressure on the electrical conductivity of PbMoO4 is more obvious than that of temperature. 相似文献
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