189 resultados para sn 2011fe


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Tin oxide doped beta-Ga2O3 single crystals are recognized as transparent conductive oxides (TCOs) materials. They have a larger band gap (4.8 eV) than any other TCOs, thus can be transparent in UV region. This property shows that they have the potential to make the optoelectronic device used in even shorter wavelength than usual TCOs. beta-Ga2O3 single crystals doped with different Sn4+ concentrations were grown by the floating zone technique. Their optical properties and electrical conductivities were systematically studied. It has been found that their conductivities and optical properties were influenced by the Sn4+ concentrations and annealing. (c) 2006 Elsevier Ltd. All rights reserved.

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Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-07-21T01:27:16Z No. of bitstreams: 1 出站报告唐黎明.pdf: 6269250 bytes, checksum: 868d0cf22419850e8dcb1acba888aeb9 (MD5)

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In this paper we present a new method for measuring diffusion coefficients in liquid metals under convection-less conditions with solid/liquid-liquid/solid trilayer. The advantage of this kind of trilayer is that effects from gravity-induced convection and Marangoni-convection can be omitted, so that the diffusion coefficient is determined more accurately. The Ta/Zn-Sn/Si trilayer were prepared with a multi-target ion-beam sputtering deposition technique and annealed in an electric furnace under an argon atmosphere. The interdiffusion of liquid zinc and tin at 500 degrees degree C was investigated. The diffusion concentration profiles were determined by energy dispersive spectroscopy. The interdiffusion coefficients range from 1.0x10(-6)cm(2)/s to 2.8x10(-6)cm(2)/s, which is less than previous values measured by capillary reservoir technique under 1g-environment where various convection exist. The precise interdiffusion coefficients of liquid zinc and tin result from the removing of disturbances of various kinds of convection.

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本文合成了LaBa_2Cu_(3-x)Sn_xO_(6.5) + x (x = 0.2; 0.5; 0.7; 1.0; 1.2; 1.5; 1.7; 2.0; 2.2; 2.5; 2.7; 3.0)系列,2aBaCu_(2-x)Sn_xO_(4.5) + x (x = 0; 0.2; 0.5; 0.7; 1.0; 1.2; 1.5; 1.7; 2.0)系列和La_3Cu_(3-x)Sn_xO_(7.5) + x (x = 0.5; 1.0; 1.5; 2.0; 2.2; 2.5; 2.7)系列等二十八个新复合氧化物。这三个系列二十八个新复合氧化物直至目前为止,文献上未见过报道。我们通过x-ray粉末衍射图分析了它们的结构,肯定了它们是新的单一化合物,计算了它们的晶胞参数并确定它们的所属晶系。元素化学分析表明,所有这些化合物均可用原始计算配比化学式表示。干湿两种合成方法所合成的结构相同。对于这三个系列二十八个瓣复合氧化物,我们选用LaBa_2-Cu_(3-x)Sn_xO_(6.5) = x (x = 0.5;1.0;1.5;2.0;2.5),LaBaCu_(2-x)Sn_xO_(4.5) = x(x = 0.5; 1.0; 1.5;2.0), La_3Cu_(3-x)Sn_xO_(7.5) + x (x = 0.5; 1.0; 1.5; 2.0; 2.5)等十四个化合物,对它们的低温,高温和高湿下的电阻率和导电类型进行了测试,绘得了它们的电阻率和温度的关系曲线。在一定温度下,一个系列内的化合物电阻率随锡的分子含量增加而增大。La_3Cu_(3-x)Sn_xO_(7.5) = x系统人物的电阻率明显大于其它二个系列相应化合物的电阻率。所有化合物在液氮至室温温区内,基本上呈半导体导电类型。在高温以上温区,当温度升至一定温度时之前,化合物呈本导体导电类型达到一定温度之后,当金属导电类型所有新复合氧化物在高温均属P型半导体。本文还研究了这三个系列化合物和将它们掺入二氧化锡中的气敏性能。结果表明:所有这类化合物和将它们掺入二氧化锡中作为添加剂做成的气敏材料,除LaBa_2Cu_(1.5)Sn_(1.5)O_8掺入SnO_2做成的气敏材料外,在本文实验条件下做成的气敏元件对氧化性和还原性气体均无或只有很差的气敏性。LaBa_2Cu_(1.5)Sn_(1.5)O_8作为添加剂掺入SnO_2中(摩尔比0.2:0.8; 0.1:0.9)所制得的气敏文件对高浓度(1%-10%)的一氧化碳,液化气和煤气具有很好的气敏线性响应,当加热电流为300mA时,酒精,汽油和石油醚等还原性气体基本上无干扰。实验表明当摩尔比为0.1:0.9时,材料的气敏性能最佳,但重现性较差,当摩尔比为0.2:0.8时,气敏性稍低,但重现性较好。本文还合成了La_xBa_(1-x)SnO_3(x = 0; 0.05; 0.10; 0.15, 0.20)系列化合物,并确定了它们的结构和所属晶系。从结构上分析我们认该系列化合物相互之间为置换固溶体。其晶胞参数随镧的加入量增加而减小。该系列均属几型半导体材料。我们利用该系列材料进行了过敏性研究。结果表明。由La_(0.1)Ba_(0.9)SnO_3制得的高热式气敏器件对低浓度酒精(<1000 ppm)有很好的气敏线性响应。在加热电流为250 mA时,基本上排除了煤气,一氧化碳,液化气和汽油等可燃性气体的干扰。但香烟烟雾对器件检测酒精有一定的影响。La_(0.1)Ba_(0.9)SnO_3气敏材料多添加1%而制得的器件,机械强度达到很好的效果,器件对酒精的灵敏度有降低,而响应浓度区间宽度增加近一倍,选择性几乎不变。该材料具有较好的实验重现性。该系列的其它化合物在本实验条件下所制得的器件对可燃性气体的敏感性较差。

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This paper analyzes the energy levels along the even-parity J=1 and 2 Rydberg series of Sn I by multichannel quantum defect theory. A good agreement between theoretical and experimental energy levels was achieved. Below 59198 cm~(-1), a total of 85 and 23 new energy levels, respectively, in the J=1 and J=2 series, which cannot be measured previously by experiments, are predicted in this work. Based on the calculated admixture coefficients of each channel, interchannel interactions were discussed in detail. The results are helpful to understand the characteristics of configuration interaction among even-parity levels in Sn I.

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采用反应热蒸发法制备掺sn的In_20_3(ITO)透明导电膜,系统研究了ITO薄膜生长的优先取向对其光电性能的影响,结果表明,ITO薄膜(400)取向的优先生长对其透过率影响很小,但可明显增加载流子迁移率,从而有效降低了薄膜的方块电阻。在两个相同的薄膜硅/单晶硅太阳能电池上分别沉积(222)和(400)ITO优先取向膜,光电转换效率分别为10.3%和12.9%,表明(400)取向更有利于提高电池效率。经优化,最佳衬底温度(T_s)为225℃,最佳氧流量(fo_2)为4sccm。在优化的沉积条件下制备ITO薄膜,其电阻率可达到4.8x10~(-4)Ω·cm,可见波段的透过率大于90%,性能指数为3.8×10~(-2)□/Ω。

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In this paper we present a new method for measuring diffusion coefficients in liquid metals under convection-less conditions with solid/liquid-liquid/solid trilayer. The advantage of this kind of trilayer is that effects from gravity-induced convection and Marangoni-convection can be omitted, so that the diffusion coefficient is determined more accurately. The Ta/Zn-Sn/Si trilayer were prepared with a multi-target ion-beam sputtering deposition technique and annealed in an electric furnace under an argon atmosphere. The interdiffusion of liquid zinc and tin at 500 degrees degree C was investigated. The diffusion concentration profiles were determined by energy dispersive spectroscopy. The interdiffusion coefficients range from 1.0x10(-6)cm(2)/s to 2.8x10(-6)cm(2)/s, which is less than previous values measured by capillary reservoir technique under 1g-environment where various convection exist. The precise interdiffusion coefficients of liquid zinc and tin result from the removing of disturbances of various kinds of convection.

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