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P. R. Poudel B. Rout D. R. Diercks Y. M. Strzhemechny F. D. Mcdaniel 《Applied Physics A: Materials Science & Processing》2011,104(1):183-188
The β-SiC nanocrystals were synthesized by the implantation of carbon ions (C−) into silicon followed by high-temperature annealing. The carbon fluences of 1×1017, 2×1017, 5×1017, and 8×1017 atoms/cm2 were implanted at an ion energy of 65 keV. It was observed that the average size of β-SiC crystals decreased and the amount of β-SiC crystals increased with the increase in the implanted fluences when the samples were annealed at 1100 °C for 1 h. However,
it was observed that the amount of β-SiC linearly increased with the implanted fluences up to 5×1017 atoms/cm2. Above this fluence the amount of β-SiC appears to saturate. The Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy, and X-ray diffraction (XRD)
techniques were used to characterize the samples. 相似文献
3.
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
4.
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
5.
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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Jiandong Zhang Jiangtao Zhao Weilin Jiang Xingcai Guan Haibo Peng Zihua Zhu 《辐射效应与固体损伤》2013,168(11-12):1027-1036
ABSTRACTTungsten (W) has been regarded as one of the most promising plasma facing materials (PFMs) in fusion reactors. The formation of bubbles and blisters during hydrogen (H) irradiation will affect the properties of W. The dependence of implantation conditions, such as fluence and energy, is therefore of great interest. In this work, polycrystalline tungsten samples were separated into two groups for study. The thick samples were implanted by 18?keV H3+ ions to fluences of 1?×?1018, 1?×?1019 and 1?×?1020 H+/cm2, respectively. Another thick sample was also implanted by 80?keV H2+ ions to a fluence of 2?×?1017 H+/cm2 for comparison. Moreover, the thin samples were implanted by 18?keV H3+ ions to fluences of 9.38?×?1016, 1.88?×?1017 and 5.63?×?1017 H+/cm2, respectively. Focused ion beam (FIB) combined with scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used for micro-structure analysis, while time-of-flight ion mass spectrometry (ToF-SIMS) was used to characterize the H depth profile. It is indicated that bubbles and blisters could form successively with increasing H+ fluence. H bubbles are formed at a fluence of ~5.63?×?1017 H+/cm2, and H blisters are formed at ~1?×?1019 H+/cm2 for 18?keV H3+ implantation. On the other hand, 80?keV H2+ ions can create more trapping sites in a shallow projected range, and thus enhancing the blisters formation with a relatively lower fluence of 2?×?1017?H+/cm2. The crack-like microstructures beneath the blisters are also observed and prefer to form on the deep side of the implanted range. 相似文献
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《Physics letters. A》1986,119(5):251-255
The annealing behaviour for a supersaturated solid solution of CuFe produced by 57Fe ions implanted into a copper film has been studied by CEMS at doses of 5×1015, 1×1016, 3×1016 and 1×1017 at/cm2. During annealing the transformation of the γ- Fe phase and isolated iron atoms to the α-Fe phase was observed with a dose of 1×1016 at/cm2 at about 440°C. Prior to α-Fe, a ferromagnetic phase with small field occured at h higher doses. The effects of radiation defects on hyperfine parameters and phase transformation are discussed in this paper. 相似文献
8.
R. P. Borges B. Ribeiro A. R.G. Costa C. Silva R. C. da Silva G. Evans A. P. Gonçalves M. M. Cruz M. Godinho 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,79(2):185-195
ZnO single crystals were implanted with Mn, Co and Ni with fluences between 1 × 1016 cm-2 and 1 × 1017 cm-2 and energy of 200 keV. Results indicate
that aggregation of transition metal ions in the as implanted state occurs only in the case of Ni.
After an annealing stage to recover the ZnO structure aggregation occurs for the higher fluences of
all implanted species. For lower concentrations paramagnetic behaviour with magnetic moments close
to those of individual ions is observed. No polarised impurity band is formed as a result of the
presence of transition metal ions and all samples show electrical conduction by carriers in
extended states of ZnO. Significant values of magnetoresistance are measured at low temperatures,
where electrical transport is described by hopping mechanisms between localized states. The sign of
the magnetoresistance is dependent of the doping ion and is correlated with the observed
aggregation. 相似文献
9.
ABSTRACT Thermally grown SiO2 thin films on a silicon substrate implanted with 100?keV silicon negative ions with fluences varying from 1?×?1015 to 2?×?1017 ions cm?2 have been investigated using Electron spin resonance, Fourier transforms infrared and Photoluminescence techniques. ESR studies revealed the presence of non-bridging oxygen hole centers, E′-centers and Pb-centers at g-values 2.0087, 2.0052 and 2.0010, respectively. These vacancy defects were found to increase with respect to ion fluence. FTIR spectra showed rocking vibration mode, stretching mode, bending vibration mode, and asymmetrical stretching absorption bands at 460, 614, 800 and 1080?cm?1, respectively. The concentrations of Si–O and Si–Si bonds estimated from the absorption spectra were found to vary between 11.95?×?1021 cm?3 and 5.20?×?1021 cm?3 and between 5.90?×?1021 cm?3 and 3.90?×?1021 cm?3, respectively with an increase in the ion fluence. PL studies revealed the presence of vacancies related to non-bridging oxygen hole centers, which caused the light emission at a wavelength of 720?nm. 相似文献
10.
Lakhwant Singh 《Journal of Macromolecular Science: Physics》2013,52(5):1041-1049
Polycarbonate (Makrofol‐N) thin films were irradiated with protons (3 MeV) under vacuum at room temperature with the fluence ranging from 1×1014 to 1×1015 protons cm?2. The change in surface morphology, optical properties, degradation of the functional groups, and crystallinity of the proton‐irradiated polymers were investigated with atomic force microscopy (AFM), UV‐VIS, and Fourier‐transform infrared (FTIR) spectroscopy, and X‐ray diffraction (XRD) techniques, respectively. AFM shows that the root mean square (RMS) roughness of the irradiated polycarbonate surface increases with the increment of ion fluence. The UV‐VIS analysis revealed that in Makrofol‐N the optical band gap decreased by 30% at highest fluence of 1×1015 protons cm?2. The band gap can be correlated to the number of carbon atoms, M, in a cluster with a modified Robertson's equation. The cluster size in the proton‐irradiated Makrofol‐N increased from 112 to 129 atoms with the increase of fluence from 1×1014 to 1×1015 protons cm?2. FTIR spectra of proton (3 MeV) irradiated Makrofol‐N showed a strong decrease of almost all absorption bands at about 1× 1014 protons cm?2. However, beyond a higher critical dose an increase in intensity of almost all characteristic bands was noticed. The appearance of a new peak at 3,500 cm?1 (‐OH groups) was observed at the higher fluences in the FTIR spectra of proton‐irradiated polycarbonate. XRD measurements showed an increase of full width at half maximum (FWHM) and the average intermolecular spacing of the main peak, which may be due to the increase of chain scission and the introduction of ‐OH groups in the proton irradiated polycarbonate. 相似文献
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Large dimensional expansion has been observed at room temperature in erbium metal films implanted at room temperature with high fluences of helium. The interferometrically measured film thickness increases linearly with fluence up to a critical dose of 3 × 1017 He+/cm2 (E = 160 keV) and is superlinear at higher fluences. Annealing at 400°C causes a reduction of the induced expansion for fluences below the critical dose without apparent release of helium. Annealing of samples implanted to fluences greater than 3.5 × 1017 He+/cm2 causes accentuated expansion which is accompanied by formation and rupture of bubbles at the film surface. 相似文献
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The effects of bombardment of 250 keV argon ions in n-type GaSb at fluences 2×1015 and 5×1015 ions cm?2 were investigated by high-resolution X-ray diffraction (HRXRD), Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). HRXRD studies revealed the presence of radiation-damaged layer (strained) peak in addition to the substrate peak. The variation in the lattice constant indicates the strain in the bombarded region. The out-of-plane (?⊥) and in-plane strains (?|) determined from the profiles of several symmetric and asymmetric Bragg reflections, respectively, were found to change with the ion fluence. Simulations of XRD patterns using dynamical theory of X-ray scattering (single-layer model) for the damaged layer yielded good fits to the recorded profiles. FTIR transmission studies showed that the optical density (α·d) of GaSb bombarded with different fluences increases near the band edge with increase in ion fluence, indicating the increase in the defect concentration. The density of the defects in the samples bombarded with different fluences was in the range of 3.20×1021–3.80×1021 cm?3. The tailing energy estimated from the transmission spectra was found to change from 12.0 to 58.0 meV with increasing ion fluences, indicating the decrease of crystallinity at higher fluences. SEM micrographs showed the swelling of the bombarded surface of about 0.33 μm for the fluence of 2×1015 ions cm?2, which increased to 0.57 μm for the fluence of 5×1015 ions cm?2. 相似文献
13.
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
14.
C.E. Christodoulides 《Physics letters. A》1978,67(1):83-86
Reordering of 〈111〉 silicon, implanted with Pb ions at energies >100 keV and fluences ~5 × 1015 cm?2 is accompanied by substantial impurity indiffusion in addition to pronounced outdiffusion and accumulation at the near surface region. 相似文献
15.
F. L. Freire Jr. C. A. Achete D. F. Franceschini G. Mariotto 《Applied Physics A: Materials Science & Processing》1994,59(6):667-672
Amorphous carbon films (a-C:H) and nitrogen incorporated carbon films [a-C:H(N)] deposited by a self-bias glow discharge have been implanted with 70 keV nitrogen ions at fluences of 0.6, 1 and 2×1017 N/cm2. The in-depth modifications caused by ion implantation were determined by means of nuclear techniques, such as Rutherford Backscattering Spectrometry (RBS), Nuclear Reaction Analysis (NRA) and Elastic Recoil Detection Analysis (ERDA), as well as by Auger Electron Spectroscopy (AES) and Raman scattering. ERDA profiles show that nitrogen implantation causes hydrogen depletion, the amount of which depends on the film composition and on the ion fluence. In a-C:H(N) films nitrogen loss was also measured. The induced structural modifications in both a-C:H and a-C:H(N) films were followed by both AES, using factor analysis, and microprobe Raman spectroscopy. They turn out to be related to the energy deposited by the incident ions. Our results indicate that the ion-beam bombardment causes in both a-C:H and a-C:H(N) films an increase of either the degree of disorder or the ratio between sp2/sp3 bonds across the hydrogen-depleted layer, which depends on the ion fluence. 相似文献
16.
Boron implanted 4145 steel was evaluated for changes in the near-surface region property such as microhardness. The surfaces when implanted with 11B+ ions at 135 keV energy to a dose 1 × 1017 ions cm?2 resulted in increase of microhardness for 10 to 40 gms of applied load. An increase upto 40% in microhardness could be observed in the specimen when annealed at 310δC for 3 hours. Furthermore, the effect of ion-beam induced intermixing of 250Å thin carbon film due to boron implantation was also studied for different doses ranging from 1 × 1017 to 3 × 1017 boron ions cm?2. An increase in microhardness with applied load was observed for 1 × 1017 ions cm?2 concentration, while hardest layer was formed at 3 × 1017 ions cm?2 dose which practically had very little effect to 10 and 20 gms of load. 相似文献
17.
Y. Li C. Tan Y. Xia J. Zhang C. Xue H. Xu P. Liu 《Applied Physics A: Materials Science & Processing》2000,71(6):689-693
Si crystals were implanted with 2.0- MeV Er+ at the doses of 5×1012 ions/cm2, 1×1014 ions/cm2, 5×1014ions/cm2, 1×1015 ions/cm2 and 2.5×1015 ions/cm2. Conventional furnace thermal annealing was carried out in the temperature range from 600 °C to 1150 °C. The depth distribution
of Er, associated damage profiles and annealing behavioar were investigated using the Rutherford backscattering spectrometry
and channelling (RBS/C) technique. A proper convolution program was used to extract the distribution of Er from the experimental
RBS spectrum. The obtained distribution parameters, projected range Rp, projected range straggling ΔRp and skewness SK were compared with those of TRIM96 calculation.The experimental Rp and SK values agree well with the simulated values, while the experimental ΔRp is larger than TRIM 96 simulated value by a factor of 18%. The damage profile of silicon crystal induced by 2.0-MeV Er+ at a dose of 1×1014 ions/cm2 was extracted using the multiple-scattering dechannelling model based on Feldman’s method, which is in a good agreement with
the TRIM96 calculation. For the samples with dose of 5×1014 ions/cm2 and more, an abnormal annealing behavioar was found and a qualitative explaination has been given.
Received: 11 October 1999 / Accepted: 28 March 2000 / Published online: 5 July 2000 相似文献
18.
Conventional and phototransferred thermoluminescence of crystalline synthetic quartz implanted with 70 keV Ar ions at fluences in the range 1?×?1014–5?×?1015?ions/cm2 is reported. The glow curves, recorded at 5°C/s from beta-irradiated samples of similar mass, show a prominent peak between 100°C and 120°C. The thermoluminescence intensity of all implanted samples was greater than that of the unimplanted one. The increase in sensitivity is attributed to a corresponding increase in the concentration of point defects, as a result of the implantation, which act as electron traps or recombination centres. Kinetic analysis carried out using the peak shape, whole glow-peak and curve-fitting methods produced values of the activation energy, frequency factor and order of kinetics that are generally independent of implantation fluence. This result suggests that implantation did not necessarily affect the nature of the electron traps. With respect to phototransferred thermoluminescence, it was observed that it only appeared in the sample implanted at the highest fluence of 5?×?1015?ions/cm2. This may be so because the concentration of deep traps produced as a result of implantation at low fluence is too low to give rise to phototransferred thermoluminescence. The intensity of the phototransferred thermoluminescence goes through a peak with illumination time. We attribute this behaviour to the relative concentration of holes at recombination centres and phototransferred electrons at shallow traps. 相似文献
19.
Abstract Rutherford backscattering (RBS) and ion induced X-ray (PIXE) channeling experiments have been used to study the damage accompanying Hg and Al implantations into Hg0.8Cd0.2 Te and its annealing as well as to determine the location of Hg in the crystal. The damage induced by the implantation of 300 keV Hg and 250 keV Al ions at room temperature was found from RBS channeling studies to reach a saturation level at doses of 1 × 1014 cm?2 and 3 × 1014 cm?2 respectively. The damage resembles that characteristic for extended defects and it anneals at ≈ 300°C. The location of the constituents of Hg implanted Hg0.8 Cd0.2 Te was studied by PIXE channeling observing the characteristic X-rays for each element. Angular scans indicate that the channels are mostly blocked by Hg atoms for both unannealed and, to a lesser extent, annealed crystals. This observation supports the suggestion that interstitial Hg atoms may be responsible for the conductivity of Hg implanted Hg1–x Cdg Te. 相似文献
20.
Nanocomposite polymer electrolyte thin films of polyvinyl alcohol (PVA)-orthophosphoric acid (H3PO4)-Al2O3 have been prepared by solution cast technique. Films are irradiated with 50 MeV Li3+ ions having four different fluences viz. 5?×?1010, 1?×?1011, 5?×?1011, and 1?×?1012 ions/cm2. The effect of irradiation on polymeric samples has been studied and characterized. X-ray diffraction spectra reveal that percent degree of crystallinity of samples decrease with ion fluences. Glass transition and melting temperatures have been also decreased as observed in differential scanning calorimetry. A possible complexation/interaction has been shown by Fourier transform infrared spectroscopy. Temperature-dependent ionic conductivity shows an Arrhenius behavior before and after glass transition temperature. It is observed that ionic conductivity increases with ion fluences and after a critical fluence, it starts to decrease. Maximum ionic conductivity of ~2.3?×?10?5 S/cm owing to minimum activation energy of ~0.012 eV has been observed for irradiated electrolyte sample at fluence of 5?×?1011 ions/cm2. The dielectric constant and dielectric loss also increase with ion fluences while they decrease with frequency. Transference number of ions shows that the samples are of purely ionic in nature before and after ion irradiation. 相似文献