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能量为200keV的Ag离子,以1×1016,5×1016,1×1017 cm-2的剂量分别注入到非晶SiO2玻璃,光学吸收谱显示:注入剂量为1×1016 cm-2的样品的光吸收谱为洛伦兹曲线,与Mie理论模拟的曲线形状一致;注入剂量较大的5×1016,1×1017 cm-2的谱线共振吸收增强,峰位红移并出现伴峰. 透射电镜观察分析表明,注入剂量不同的样品中形成的纳米颗粒的大小、形状、分布都不同,注入剂量较大的还会产生明显的表面溅射效应,这些因素都会影响共振吸收的峰形、峰位和峰强. 当注入剂量达到1×1017 cm-2时,Ag纳米颗粒内部可能还形成了杂质团簇.
关键词:
离子注入
纳米颗粒
共振吸收
红移 相似文献
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采用离子注入法制备了钴离子掺杂的金红石相TiO2样品;离子注入能量、注量分别为40 keV(1×1016cm-2),80 keV(5×1015,1×1016,5×1016,1×1017cm-2),120 keV(1×1016cm-2). 通过XRD,XPS和UV-Vis等手段对掺杂前后样品的结构和光学性能进行了表征,分析了掺杂元素在金红石TiO2中的存在形式. XRD测试表明随着注入能量的增加晶体的损伤程度增加. UV-Vis测试表明掺杂后所有样品在可见光区的吸收增强; 并且随着注量的增加,注量为5×1015cm-2到5×1016cm-2范围内注入样品的光学带隙逐渐变小.
关键词:
钴
二氧化钛
离子注入
掺杂 相似文献
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本文用固相反应烧结制备出Li2Mo2O6多晶材料。经X射线分析、红外光谱和电子顺磁共振谱(EPR)的研究,确定了它的结构是Li2Mo2O4和MoO2两个晶相组成的烧结体。钼离子以四价状态存在于MoO2晶相结构中。采用交流阻抗谱分析了晶界与温度变化的相关性。测得了样品的ln(σ总T)-1/T 曲线是由两段直线和一段曲线所组成;总电导率化能σ27℃=1.36×10-3(Ω·cm)-1,σ115℃=1.49×10-3(Ω·cm)-1,σ300℃=9.71×10-3(Ω·cm)-1,σ370℃=2.42×10-3(Ω·cm)-1;电导活化能E1=0.043eV,E2=0.235eV,E平均=0.76eV。采用维格纳极化电池法测得电子电导率σe,σe27℃=2.240×10-5(Ω·cm)-1,σe300℃=4.476×10-3(Ω·cm)-1。实验证明,室温下材料为固体电解质,300℃附近为良好的离子与电子混合导体。
关键词: 相似文献
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本文中,我们研究了砷化镓中质子注入及退火恢复过程。实验用晶向<100>偏1—3°,掺Sn 5×1017-1×1018cm-3的单晶,室温下质子注入,注入能量E约8×104—2×106eV,用A-B腐蚀剂对注入质子样品的解理面显结,测得质子注入高阻层的纵向深度xj和径向扩展xL与注入能量E的定量关系。然后,对注入质子样品,在150—800℃下退火5分钟,用双晶衍射仪研究了样品的应变恢复过程,在静电计上测量了高阻阻值随退火温度的变化。根据实验结果,讨论了砷化镓中质子注入的射程Rp,电子阻止本领Sn(E)和核阻止本领Se(E),以及质子注入形成高阻和退火恢复的机理。
关键词: 相似文献
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采用电子回旋共振等离子体化学气相淀积(ECR-CVD)法,以C4F8和CH4为源气体制备了非晶氟化碳(a-C:F)薄膜.X射线电子能谱(XPS)和傅里叶变换红外光谱(FTIR)分析表明,a-C:F薄膜退火后厚度减小是由于位于a-C:F薄膜交联结构末端的C—C和CF3结合态的热稳定性较差,导致退火时容易生成气态挥发物造成的.a-C:F膜介电常数在300℃氮气气氛中退火后由于电子极化增大和薄膜密度增加而上升,界面态陷阱密度从(5—9)×1011eV-1·cm-2降至(4—6)×1011eV-1·cm-2.a-C:F薄膜导电行为在低场强区域呈现欧姆特性,在高场强区域符合 Poole-Frankel机理.非定域π电子在带尾形成陷阱且陷阱能量在退火后降低,从而使更多陷阱电子在场增强热激发作用下进入导带并引起电流增大.
关键词:
a-C:F
ECR-CVD
键结构
电学性质 相似文献
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ABSTRACTIn the present work, effects of silicon negative ion implantation into semi-insulating gallium arsenide (GaAs) samples with fluences varying between 1?×?1015 and 4?×?1017?ions?cm?2 at 100?keV have been described. Atomic force microscopic images obtained from samples implanted with fluence up to 1?×?1017?ion?cm?2 showed the formation of GaAs clusters on the surface of the sample. The shape, size and density of these clusters were found to depend on ion fluence. Whereas sample implanted at higher fluence of 4?×?1017?ions?cm?2 showed bump of arbitrary shapes due to cumulative effect of multiple silicon ion impact with GaAs on the same place. GXRD study revealed formation of silicon crystallites in the gallium arsenide sample after implantation. The silicon crystallite size estimated from the full width at half maxima of silicon (111) XRD peak using Debye-Scherrer formula was found to vary between 1.72 and 1.87?nm with respect to ion fluence. Hall measurement revealed the formation of n-type layer in gallium arsenide samples. The current–voltage measurement of the sample implanted with different fluences exhibited the diode like behavior. 相似文献
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V. Popok V. Odzhaev V. Hnatowicz J. Kvítek V. Švorčik V. Rybka 《Czechoslovak Journal of Physics》1994,44(10):949-956
Silicon wafers were implanted with 40 keV B+ ions (to doses of 1.2×1014 or 1.2×1015 cm–2) and 50 or 100 keV N+ ions (to doses from 1.2×1014 to 1.2×1015 cm–2). After implantations, the samples were furnace annealed at temperatures from 100 to 450 °C. The depth profiles of the radiation damages before and after annealing were obtained from random and channeled RBS spectra using standard procedures. Two damaged regions with different annealing behaviour were found for the silicon implanted with boron ions. Present investigations show that surface disordered layer conserves at the annealing temperatures up to 450 °C. The influence of preliminary boron implantation on the concentration of radiation defects created in subsequent nitrogen implantation was studied. It was shown that the annealing behaviour of the dual implanted silicon layers depends on the nitrogen implantation dose.The authors would like to thank the members of the INP accelerator staff for the help during the experiments. The work of two authors (V.H. and J.K.) was partially supported by the Internal Grant Agency of Academy of Science of Czech Republic under grant No. 14805. 相似文献
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T. Shimada Y. Kato Y. Shiraki K.F. Komatsubara 《Journal of Physics and Chemistry of Solids》1976,37(3):305-313
Two types of non-crystalline states (“disordered” and “amorphous”) of GaP were produced by using ion implantation and post annealing. A structural-phase-transition-like annealing behaviour from the “disordered” state to the “amorphous” state was observed.The ion dose dependence and the annealing behaviour of the atomic structure of GaP implanted with 200 keV ? N+ ions were studied by using electron diffraction, backscattering and volume change measurements. The electronic structure was also investigated by measuring optical absorption and electrical conductivity.The implanted layer gradually loses the crystalline order with the increase of the nitrogen dose.The optical absorption coefficient α and electric conductivity σ of GaP crystals implanted with 200 keV?N+ ions of 1 × 1016 cm?2 were expressed as αhν = C(hν ? E0)n and log , respectively. Moreover, the volume of the implanted layer increased about three percent and the electron diffraction pattern was diffused halo whose intensity monotonically decreases along the radial direction. These results indicate that the as-implanted layer has neither a long range order nor a short range order (“disordered state”).In the sample implanted at 1 × 1016 cm?2, a structural phase-transition-like annealing stage was observed at around 400°C. That is, the optical absorption coefficient α abruptly fell off from 6 × 104 to 7 × 103 cm?1 and the volume of the implanted layer decreased about 2% within an increase of less than 10 degrees in the anneal temperature. Moreover, the short range order of the lattice structure appeared in the electron diffraction pattern. According to the backscattering experiment, the heavily implanted GaP was still in the non-crystalline state even after annealing.These facts lead us to believe that heavily implanted GaP, followed by annealing at around 400°C, is in the “amorphous” state, although as-implanted Gap is not in the “amorphous” state but in the “disordered” state. 相似文献
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A. Colder P. Marie T. Wojtowicz P. Ruterana S. Eimer L. Mchin K. Lorenz U. Wahl E. Alves V. Matias M. Mamor 《Superlattices and Microstructures》2004,36(4-6):713
Deep level transient spectroscopy (DLTS) was used to investigate the electrical properties of GaN implanted with the rare earth (RE) ions erbium and thulium. The GaN layers have been grown by metal-organic chemical vapor deposition (MOCVD) onto (0001) sapphire substrates. We used the channeled implantation geometry to implant a dose of 5×1014 RE cm−2 with an energy of 150 keV. For each species, two different annealing procedures were used in a nitrogen atmosphere for 120 s. Indeed, the annealing temperature plays an important role in the lattice recovery, even if RE-related defects remain present. After annealing at 1000 C, the appearance of two new peaks, for both studied RE ions, is associated with the lattice damage induced by the implantation, such as the presence of nitrogen vacancies. After annealing at 1100 C, the recovery of the lattice is observed while a hole trap appears for both implanted RE ions with corresponding energy values Ev+0.61 eV and Ev+1.59 eV, in the case of Er and Tm, respectively. 相似文献
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Pure iron foils were implanted with nitrogen ions at energy of 10 keV and with 1×1017N ions/cm2. Doses of pre-self-implantation were 5×1016 and 3.7×1016
17Fe ions/cm2 respectively, and the iron ion energy was 27 keV. A comparison of iron nitrides formed on surfaces with and without pre-self-implantation
has been obtained. The results show that radiation damage apparently influences the formation of iron nitrides. The formation
and transformation of nitrides after N implantation or after annealing can be explained by a model of implantation-induced
transformation. 相似文献
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Many studies have been done on low energy (1–200 keV) and high dose (1016–1017) implantation of Mn in GaAs. This study is an attempt to incorporate Mn ions in GaAs through implantation of 1 MeV Mn+1 ions in semi-insulating GaAs substrates at doses of 3×1015/cm2 and subsequent annealing. This was done to find out if any alloy of Mn–Ga–As, or binary compounds of Mn–Ga or Mn–As form
due to annealing of Mn+1 ions implanted in GaAs substrates. High Resolution XRD (HRXRD) performed before annealing shows a possibility of Ga–Mn–As
alloy formation, and after annealing at 800°C, except for GaAs main peaks no other phase peaks were detected. Scanning electron
microscopy (SEM) shows nanostructures of various dimensions which are thought to be formed due to the defects generated due
to implantation. Fourier Transform Infrared (FTIR) study shows the shift in bandgap due to Mn doping. Raman spectroscopy shows
the red shift in LO and TO peak positions of GaAs after annealing, which indicates the presence of disorder and damage due
to implantation. Resistivity measurement shows a thermally activated semiconductor character of charge conduction with an
activation energy of 51 meV and this activation may have occurred through the transitions from impurity band to valence band.
Large positive (∼25%) magnetoresistance and a mixture of ferromagnetic and paramagnetic behavior obtained in the magnetization
measurement indicate the presence of ferromagnetic MnAs nanoclusters embedded in paramagnetic GaAs:Mn matrix. 相似文献
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Transition Metal (TM) ions V, Cr, Mn and Co were implanted into GaN/sapphire films at fluences 5×1014, 5×1015 and 5×1016 cm−2. First order Raman Scattering (RS) measurements were carried out to study the effects of ion implantation on the microstructure of the materials, which revealed the appearance of disorder and new phonon modes in the lattice. The variations in characteristic modes 1GaN i.e. E2(high) and A1(LO), observed for different implanted samples is discussed in detail. The intensity of nitrogen vacancy related vibrational modes appearing at 363 and 665 cm−1 was observed for samples having different fluences. A gallium vacancy related mode observed at 277/281 cm−1 for TM ions implanted at 5×1014 cm−2 disappeared for all samples implanted with rest of fluences. The fluence dependent production of implantation induced disorder and substitution of TM ions on cationic sites is discussed, which is expected to provide necessary information for the potential use of these materials as diluted magnetic semiconductors in future spintronic devices. 相似文献
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High purity <100> wafers of GaAs were implanted with radioactive129mTe and stable128Te at 110 keV to total doses of 2×1014 and 2×1015 Te/cm2 respectively and studied with RBS/ channeling and Mössbauer spectroscopy on the 27.8 keV level of129I. After implantation and/or annealing at temperatures between 200–300°C the Mössbauer spectra are dominated by a single line. Channeling reveals an appreciable residual damage in the host lattice, but also points to a substitutional position of the Te atoms. After annealing above ≌500°C, where nearly complete lattice damage recovery is obtained, the Te atoms become defect-associated. The results clearly point to the formation of TeAs?VGa complexes. 相似文献