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101.
Large single crystals of Pb1-xGexTe (0 < × < 0.105) up to 10 g and Pb1-ySnyTe (0 < y < 0.26) up to 125 g were grown in sealed
tubes by self-transport onto oriented single crystal seeds. The crystals were free of voids and inclusions, had dislocation
densities as low as 103 cm-2, and were uniform in composition. Pertinent details of the growth technique, including thermal
conditions, stoichiometry of the source, and seed orientation, are described. Results of evaluation of the crystals by metallography,
Laue X-ray topography, and electron microprobe analysis are presented. 相似文献
102.
D. Kumar R. D. Vispute O. Aboelfotoh S. Oktyabrsky K. Jagannadham J. Narayan P. R. Apte R. Pinto 《Journal of Electronic Materials》1996,25(11):1760-1766
Metallization of high-Tc superconductors using low resistivity metal oxides and Cu-Ge alloys has been investigated on high quality pulsed laser deposited
epitaxial YBa2Cu3O7-x (YBCO) films. Epitaxial LaNiO3 (LNO) thin films have been grown on YBCO films at 700°C using pulsed laser deposition. The specific resistivity of LNO was
measured to be 50 μΩ-cm at 300K which decreases to 19 μΩ-cm at 100K indicating good metallicity of the LNO films. The contact
resistance of LNO-YBCO thin film interface was found to be reasonably low (of the order of 10-4Ω-cm2 at 77K) which suggests that the interface formed between the two films is quite clean and LNO can emerge as a promising metal
electrode-material to YBCO films. A preliminary investigation related to the compatibility of Cu3Ge alloy as a contact metallization material to YBCO films is discussed. The usage of other oxide based low resistivity materials
such as SrRuO3 (SRO) and SrVO3 (SVO) for metallization of high-Tc YBCO superconductor films is also discussed. 相似文献
103.
本工作测定了136cm~3同轴型锗(锂)探测器在不同能量下的全能峰绝对效率。在引入有效作用深度后,用半经验参数法对实测的绝对效率值作了非线性最小二乘拟合。拟合值与实验值符合良好。 相似文献
104.
The intermetallic compounds formed in Sn3Ag0.5Cu and Sn3Ag0.5Cu0.06Ni0.01Ge solder BGA packages with Ag/Cu pads are investigated.
After reflow, scallop-shaped η-Cu6Sn5 and continuous planar η-(cu0.9Ni0.1)6Sn5 intermetallics appear at the interfaces of the Sn3Ag0.5Cu and Sn3Ag0.5Cu0.06Ni0.01Ge solder joints, respectively. In the
case of the Sn3Ag0.5Cu specimens, an additional ε-Cu3Sn intermetallic layer is formed at the interface between the η-Cu6Sn5 and Cu pads after aging at 150°C, while the same type of intermetallic formation is inhibited in the Sn3Ag0.5Cu0.06Ni0.01Ge
packages. In addition, the coarsening of Ag3Sn precipitates also abates in the solder matrix of the Sn3Ag0.5Cu0.06Ni0.01Ge packages, which results in a slightly higher
ball shear strength for the specimens. 相似文献
105.
介绍了锗掺杂浓度为(1~1.5) E19cm-3的10Ω·cm磁控直拉单晶硅衬底上BSFR (back surface field and reflection)和BSR(back surface reflection)太阳电池的制备和电性能. BSR锗掺杂单晶硅太阳电池的AM0效率最高为12.3%. BSFR锗掺杂单晶硅太阳电池的AM0效率达到15%. 利用1MeV的高能电子对制备的锗掺杂单晶硅太阳电池进行了辐照实验. 作为对比,对全部常规10Ω·cm的CZ单晶硅太阳电池也进行了实验. 结果表明,锗掺杂浓度为(1~1.5)E19cm-3的磁控直拉单晶硅太阳电池的电性能和抗辐照性能与常规直拉硅太阳电池基本相同. 利用锗掺杂磁控直拉单晶硅片机械强度较高的优点,可以降低太阳电池生产过程破损率. 相似文献
106.
A. Rastelli M. Stoffel G. Katsaros J. Tersoff U. Denker T. Merdzhanova G.S. Kar G. Costantini K. Kern H. von Knel O.G. Schmidt 《Microelectronics Journal》2006,37(12):1471-1476
We report on recent advances in the understanding of surface processes occurring during growth and post-growth annealing of strained islands which may find application as self-assembled quantum dots. We investigate the model system SiGe/Si(0 0 1) by a new approach based on “reading the footprints” which islands leave on the substrate during their growth and evolution. Such footprints consist of trenches carved in the Si substrate. We distinguish between surface footprints and footprints buried below the islands. The former allow us to discriminate islands which are in the process of growing from those which are shrinking. Islands with steep morphologies grow at the expense of smaller and shallower islands, consistent with the kinetics of anomalous coarsening. While shrinking, islands change their shape according to thermodynamic predictions. Buried footprints are investigated by removing the SiGe epilayer by means of selective wet chemical etching. Their reading shows that: (i) during post-growth annealing islands move laterally because of surface-mediated Si–Ge intermixing; (ii) a tree-ring structure of trenches is created by dislocated islands during their “cyclic” growth. This allows us to distinguish coherent from dislocated islands and to establish whether the latter are the result of island coalescence. 相似文献
107.
P. Johansson 《Thin solid films》2006,515(2):477-480
Bismuth iron garnet (Bi3Fe5O12, BIG) epitaxial thin films were grown on single crystal (Gd3Ga5O12, GGG) (111) and (001) substrates by rf-magnetron sputtering technique. Processing parameters have been optimized to obtain high deposition rate (2.74 μm/h) and the surface rms roughness less than 10 nm. X-ray diffraction reveals films epitaxial quality: exclusive (111) or (001) orientation with narrow rocking curves and strong in-plane texture. Films possess low optical loss and magneto-optical Faraday rotation (FR) as high as 5 deg/μm at 677 nm wavelength. Comparative analysis of films grown on (111) and (001) substrates clearly shows significant superiority of BIG/GGG(001) film. For this film, the coercive field ∼100 Oe appears to be 2.5 times lower while the optical transmission to be 10% higher than that for BIG/GGG(111) film. Enhanced magneto-optical performance of BIG/GGG(001) films relies upon better accommodation of the film-to-substrate mismatch strain through the tetragonal BIG lattice distortions compared to the rhombohedral one in BIG/GGG(111) films. 相似文献
108.
109.
采用离子束溅射方法在Si衬底上制备Si/Ge多层膜,通过改变生长温度、溅射速率等因素得到一系列Si/Ge多层膜样品;通过X射线衍射、Raman散射等表征方法研究薄膜结构与生长条件的关系。在小束流(10mA)、室温条件下制备出界面清晰、周期完整的Si/Ge多层膜。 相似文献
110.
Tiecheng Lu Shaobo Dun Qiang Hu Songbao Zhang Zhu An Yanmin Duan Sha Zhu Qiangmin Wei Lumin Wang 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2006,250(1-2):183-187
A Ge nano-layer embedded in the surface layer of an amorphous SiO2 film was fabricated by high-fluence low-energy ion implantation. The component, phase, nano-structure and luminescence properties of the nano-layer were studied by means of Rutherford backscattering, glancing incident X-ray diffraction, laser Raman scattering, transmission electron microscopy and photoluminescence. The relation between nano-particle characteristics and ion fluence was also studied. The results indicate that nano-crystalline Ge and nano-amorphous Ge particles coexist in the nano-layer and the ratio of nano-crystalline Ge to nano-particle Ge increases with increasing ion fluence. The intensity of photoluminescence from the nano-layer increases with increasing ion fluence also. Prepared with certain ion fluences, high-density nano-layers composed of uniform-sized nano-particles can be observed. 相似文献