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1.
离子辐照钨基上碳薄膜微结构的分析 总被引:1,自引:0,他引:1
对钨基材料表面上射频磁控溅射沉积的碳膜进行了氩离子和氮离子的辐照,并作了XRD及XPS的分析。分析结果表明,不同离子辐照引起碳膜微结构的变化亦不同,。氮离子辐照不仅使碳膜元素与基体元素发生混合,而且导致碳膜发生相变,生成碳-化合物,如α-W2C、WCx,同时氮离子本身与反应生成氮-钨化合物,如a-WN。 相似文献
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S. Nagata H. Fujita S. Yamamoto T. Shikama 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(19):3151-3154
The optical changes in amorphous WO3 film prepared by reactive RF sputtering and irradiated by 200-800 keV oxygen ions were measured to study the relationship between coloration and energy deposition. The color centers were effectively created by ion irradiation with contributions from nuclear collisions and electronic energy loss. The increase in the absorption coefficient was reasonably explained by a first order reaction, whose production rate depended roughly on the total deposited energy. During heat treatment in air atmosphere, transmittance recovery started at 400 K and completed at 550 K. No significant difference was found among films irradiated by different incident energies; therefore indicating that the ion-induced damage structure is not strongly influenced by the type of energy loss. 相似文献
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N. Endstrasser B. Rasul K. Krieger P. Scheier 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(4):700-703
Sticking coefficients of deuterium from are quantified on fusion relevant plasma sprayed tungsten and carbon fibre composite in the incident energy range from about 0-100 eV. The samples that were cut from ASDEX-Upgrade tiles are exposed to a beam of of specific incident energy, Einc, in the tandem mass spectrometer BESTOF in Innsbruck. Nuclear reaction analysis is performed ex-situ at IPP Garching for the quantification of deuterium content. The deuterium content difference measured on a spot before and after ion-beam exposure of the sample is assigned to the above mentioned species of hydrocarbon molecules sticking on the surface, allowing the calculation of the sticking probability of a specific deuterated molecular ion. The sticking coefficient, S, is found to depend on the incident energy and shows a maximum of about S ∼ 0.4 around Einc = 30 eV on CFC and about S ∼ 0.1 near Einc = 20 eV in case of PSW. 相似文献
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NI Zhichun LI Qintao YAN Long GONG Jinlong ZHU Dezhang ZHU Zhiyuan 《核技术(英文版)》2007,18(3):137-140
Multi-walled carbon nanotubes were irradiated with 40 keV Si ion beam to a dose of 1×10^7 cm^-2. The multiple-way carbon nanowire junctions and the Si doping in carbon nanowires were realized. Moreover, the formation processes of carbon nanowire junctions and the corresponding mechanism were studied. 相似文献
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离子辐照聚合物薄膜引起的降解和能量传输过程 总被引:2,自引:0,他引:2
用120keVN^+,Ar^+,Fe^+辐照聚酰亚胺薄膜,辐照剂量为5×10^14-1×10^17ions/cm^2,对辐照样品做了表面电阻和光学吸收数量,结果表明:辐照后样品的表面电阻有明显变化,且随辐照剂量变化呈现阈值,在高剂理下达到饱和值。 相似文献
8.
高能Ar离子辐照PET膜引起的表面改性研究 总被引:2,自引:0,他引:2
采用傅立叶转换的红外光吸收技术在反射方式下分析研究了35MeV/u Ar离子辐照半晶质PET膜引起的表面改性及其对吸收剂量的依赖性。结果表明,辐照导致PET膜中与晶态区域相关的吸收带强度随吸收剂量增加普遍减弱,而与非晶区域相关的吸收带强度随吸收剂量增加逐渐增加,表明辐照使PET膜发生了非晶化转变。化学键断裂主要发生在苯环的对位和酯的C-O键上,而苯环的基本结构在整个辐照过程中变化较小。非晶化效应和化学键断裂同时依赖于离子的照射剂量和样品表面的电子能量沉积。此外,在约5.0MGy以上的吸收剂量,辐照还引起了炔端基团的形成,炔端基团浓度随吸收剂量的增加显著增加。对实验结果进行了定性解释。 相似文献
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S.X. JinL.P. Guo Z. YangD.J. Fu C.S. LiuW. Xiao R. TangF.H. Liu Y.X. Qiao 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(3):209-215
Irradiation damage in nickel alloy C-276 irradiated by 115 keV argon ions at room temperature with irradiation doses from 0.28 to 82.5 dpa has been investigated by transmission electron microscopy. Nano-scale black spot damage appeared at a dose higher than 0.83 dpa. Large interstitial-type dislocation loops were observed at the dose of 8.25 dpa. Both the density of dislocation loops and the density of network dislocations grew significantly with the increase of irradiation dose. However, the density of network dislocations declined at the dose of 27.5 dpa. But the total of dislocation density (density of dislocation lines plus density of dislocation loops) kept increasing and no signs of saturation were seen in the dose range explored. The results showed that the nickel alloy C-276 had good performance in delaying the development of black spots, dislocations and dislocation loops. However, original grains have formed into subgrains at the dose of 82.5 dpa, meaning that the grains in C-276 lost its structural integrity at doses higher than 82.5 dpa. 相似文献
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ecreases in irradiated MWCNT sheets can be ascribed to the increase of defects in the irradiated MWCNTs. 相似文献
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Z. Tian 《Journal of Nuclear Materials》2010,399(1):101-107
Deuterium retention in two types of polycrystalline tungsten (PCW) was studied as a function of incident ion fluence, ion energy, and specimen temperature. (i) D retention at 300 K, as a function of D+ fluence, demonstrated a trend to saturation in both the Rembar hot-rolled thin foil and Plansee tungsten plate. At 500 K, new D retention results for the Plansee PCW showed an increasing trend with increasing incident D+ fluence without any indication of saturation, in agreement with previous results for Rembar PCW [A.A. Haasz, J.W. Davis, M. Poon, R.G. Macaulay-Newcombe, J. Nucl. Mater. 258-263 (1998) 889-895]. Even when the incident D+ fluence was increased to 8 × 1025 D+/m2, which is in the fluence range of plasma devices, there was still no sign of saturation. (ii) The temperature dependence results for the Plansee PCW show a decreasing trend in D retention as the temperature is increased from 300 to 500 K. These results differ from previous studies of Rembar PCW [A.A. Haasz, J.W. Davis, M. Poon, R.G. Macaulay-Newcombe, J. Nucl. Mater. 258-263 (1998) 889-895], but are similar to those seen for single crystal tungsten [M. Poon, A.A. Haasz, J.W. Davis, R.G. Macaulay-Newcombe, J. Nucl. Mater. 313-316 (2003) 199]; an explanation for the different behaviour is suggested. (iii) Varying the D+ energy from 100 to 500 eV/D+ plays a minor role in the amount of D retained, suggesting that D retention in W depends more on the W structure, incident ion fluence and specimen temperature, rather than on the incident ion energy when the energy is below the threshold for damage formation (∼960 eV for D on W). 相似文献
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Assel Aitkaliyeva Michael C. McCarthy Michael Martin E.G. Fu D. Wijesundera Xuemei Wang Wei-Kan Chu Hae-Kwon Jeong Lin Shao 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(20):3443-3446
We studied the frequency shifts in G, D and D* Raman modes in freestanding multiwall carbon nanotube buckypapers. Upon ion irradiation by 140 keV He+ or 3 MeV H+ ions, the intensity ratio of D–G modes linearly increases with fluence before amorphization. The ratio is used to quantitatively measure the level of disorder in the buckypaper. The study shows that, upon post-irradiation annealing, defect removal requires little energy addition in lightly damaged buckypaper, which is evidenced by an activation energy of 0.36 eV. Once amorphized, defect removal becomes very difficult. The D–G intensity ratio has no reduction in heavily damage sample after annealing up to 850 °C. 相似文献
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S. Moll L. Thomé C. Legros 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(19):2933-2936
Pyrochlore pellets with the Gd2(Ti2−xZrx)O7 stoichiometry (x = 0, 1 and 2) were irradiated with swift heavy ions in order to investigate the effects of electronic excitation and to determine the electronic stopping power threshold for track formation. XRD results showed that the electronic excitation induced by 870 MeV Xe and 780 MeV Kr ions leads to: (i) a crystalline-amorphous transition for Gd2Ti2O7 and Gd2TiZrO7, (ii) a phase transition towards an anion-deficient fluorite structure (order-disorder transition) for Gd2Zr2O7. Thus, zirconate pyrochlores present a better radiation resistance under swift heavy ion irradiation than titanate pyrochlores. Moreover results underline the existence of an electronic stopping power threshold around 13-14 keV/nm, below which phase transformations do not occur. 相似文献
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L.G. Jacobsohn J.D. Thompson Y. Wang A. Misra R.K. Schulze M. Nastasi 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2006,250(1-2):201-205
The effects of ion irradiation of 3-dimensional arrays of Co nanoparticles were investigated. Arrays were obtained by electron beam deposition of 15 Co/SiO2 bilayers 0.5 and 20 nm thick, respectively. The Co layers consist of Co nanoparticles 3.2 nm in diameter with a standard deviation of 16%. Irradiation was carried out using combinations of 150 kV Ar2+ and 90 kV Ar+ ion bombardments with a Ar+:Ar2+ fluence ratio of 1:4. The effects of ion irradiation were followed by Rutherford backscattering, measurements of hysteresis loops at 5 K and of temperature-dependent field-cooled (FC) and zero-field-cooled (ZFC) measurements of the magnetic susceptibility. A decrease of the peak temperature in the ZFC curve for displacements per atom (DPA) up to 1.1 was observed. Irradiation also induces progressively lower coercivity values. The Co particles showed a remarkable high resistance to ion irradiation, surviving damage up to 33 DPA. 相似文献
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《核技术(英文版)》2016,(2):131-135
Irradiation tests of tungsten surface were performed with He and He/Ar plasma generated by microwave electron cyclotron resonance. Thickness loss was used as the erosion rate of tungsten surface under the plasma irradiation. The results revealed that the thickness loss increased linearly with negative bias. SEM images proved that the addition of Ar apparently increased the plasma erosion. The thickness loss increased sharply with the Ar fraction of Ar/He mixture when it was \20 %,where the increasing slope of thickness loss lowered down gradually. 相似文献
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Alejandro G. Perez-Bergquist Fabian U. NaabYanwen Zhang Lumin Wang 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(6):561-565
In this study, porous silicon was fabricated without any chemical etching by self-ion implantation of crystalline Si performed at high temperature and at high fluences. The irradiated silicon samples, which remained crystalline under high temperature ion irradiation, exhibited an increased porous fraction with increasing sample temperature at a given fluence, up to the maximum tested temperature of 650 °C. Extremely high ion fluences of at least 2 × 1018 ions/cm2 were necessary to produce significant void growth. Comparisons between the porous silicon structures and irradiation-induced porous networks in Ge, GaSb, and InSb are made, and differences in the formation conditions for these porous networks are discussed. 相似文献
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The collison-induced reaction of Na^ ion with neutral C60 vapour was investigated at the energy range of 10 to 150eV.The deposited films were studied via laser desorption time-of-flight mass spectroscopy(TOFMS).The fragment products of C60 with even number of carbon atoms,such as Cn^ (n=58,56,54),and adduct products,such as Cn^ (n=62,64,66,68) were observed in the positively charged TOF mass spectra.The endohedral fullerene ion of Na @C60^ was detected when collision energies are above 20eV.Besides,no negative endohedral fullerene was detected,the products appearing in positively charged mass spectra were also observed in the negatively charged mass spectra.In addidtion,a series of products with odd number of carbon atoms,such as Cn^-(n=53,55,57,59,61,63,65,67),also appeared.but the intensities of their signals were not as high as that of even numbered.Finally,it is interesting to find that the deposited films are insoluable in toluene,benzene or water.Their Fourier transform infrared (FTIR),spectra seem like those photopolymerized ones.Some of the reaction schemes are proposed to explain the experimental results. 相似文献
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Natalya N. AndrianovaAnatoly M. Borisov Eugenia S. Mashkova Yury S. Virgiliev 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(9):861-864
The ion-induced erosion, determining by sputtering yield Y and surface evolution including structure and morphology changes of the modified surface layers, of two commercial carbon fiber composites (CFC) with different reinforcement - KUP-VM (1D) and Desna 4 (4D) have been studied under 30 keV Ar+ high fluence (φt ∼ 1018-1020 ion/cm2) irradiation in the temperature range from room temperature to 400 °C. Ion-induced erosion results in the changes of carbon fiber structure which depend on temperature and ion fluence. Monitoring of ion-induced structural changes using the temperature dependence of ion-induced electron emission yield has shown that for Desna 4 and KUP-VM at dynamic annealing temperature Та ≈ 170 °С the transition takes place from disordering at T < Ta to recrystallization at T > Ta. The annealing temperature Та is close to the one for polycrystalline graphites. Microscopy analysis has shown that at temperatures Т < Ta the etching of the fibers results in a formation of trough-like longitudinal cavities and hillocks. Irradiation at temperatures T > Ta leads to a crimped structure with the ribs perpendicular to fiber axis. After further sputtering of the crimps the fiber morphology is transformed to an isotropic globular structure. As a result the sputtering yield decreases for Desna 4 more than twice. This value is almost equal to that for KUP-VM, Desna 4, polycrystalline graphites and glassy carbons at room temperature. 相似文献
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对30keV氮离子束辐照5’edTMP核苷酸引起的无机磷和碱基的释放进行了多方面的研究,得到无机磷产率和碱基产生量的剂量效应曲线。以及0.1mol/LNaOH碱处理对它们的影响。碱处理不仅增加了无机磷的释放量,而且还使辐照产生的游离碱基受到损伤而裂解。碱处理后立刻测量得知,受辐照样品的碱溶液中无机磷的含量为其水溶液中的17倍,而样品碱溶液中的碱基浓度却只有其水溶液中的0.5倍左右,碱处理40min后,受辐照样品之碱溶液中无机磷含量则增至其水溶液中的2.8倍左右。另外,离子束辐照作用主要是直接作用,具有较高的G(Pi)值,达0.44分子/100eV以上。 相似文献