共查询到20条相似文献,搜索用时 11 毫秒
1.
Y. TaharaB. Zhu S. KosugiN. Ishikawa Y. OkamotoF. Hori T. MatsuiA. Iwase 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(9):886-889
To simulate the effects of Gd2O3-doping and high-energy fission products in UO2, Gd2O3-doped CeO2 pellets were irradiated with 200-MeV Xe14+ ions. Doping and irradiation effects were analyzed using X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS). The lattice constant of CeO2 decreases and the local structure is disordered with increased doping levels. However, the irradiation induces an expansion of the lattice and a disordering of atomic arrangement near the Gd atoms. The effects of the irradiation become more pronounced with increasing Gd2O3-dopant levels. Our results are compared with those of a study involving Er2O3-doped CeO2. 相似文献
2.
F.Y. Xi H.P. Liu X.M. Chen 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(13):2292-2294
We made an experimental study on ion guiding through capillaries in uncoated Al2O3 membranes using a variety of ions such as O1+, O3+, and O6+. The incident energy was varied within the range of 30-150 keV. The results were compared with others using coated PET and Al2O3 capillary membranes as well as with the so-called scaling law discovered by Stolterfoht and his co-workers. Good agreement of our results with the scaling law was found. However, our membranes showed extraordinarily strong guiding ability. The reason lies in that our membranes were uncoated. A slower charge drift speed along the insulating capillary wall and a much larger equilibrium charge Q∞ seems to exist in our experiment. 相似文献
3.
B. Zhu S. Kosugi K. Yasunaga A. Iwase 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(19):3199-889
In order to simulate the effects of burnable poison doping on the fission fragment damage of UO2 nuclear fuels, Er2O3-doped CeO2 pellets were irradiated with 200 MeV Xe14+ ions. The irradiation effect was measured by means of X-ray diffraction (XRD). The expansion of lattice and the disordering of atomic arrangement due to the irradiation become more remarkable with increasing the concentration of the Er2O3 dopant. 相似文献
4.
5.
6.
Jingjing LiuStephen Hull Istaq Ahmed Stephen J. Skinner 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(5):539-543
In-situ neutron diffraction combined with AC impedance spectroscopy was applied successfully to investigate the correlation between crystal structure and electrical properties of the La2Mo2O9 oxide ion conducting electrolyte material. Neutron diffraction patterns were collected as a function of temperature while the AC impedance spectra were recorded simultaneously using a modified sample environment to monitor the conductivity change of the sample. A close relationship between unit cell parameters and the bulk conductivity was observed, confirming that the oxygen transport is dependent on the lattice structure. With the transition from the low temperature alpha to the high temperature beta phase, expansion of the crystal structure makes more space available for oxygen transport, leading to a dramatic increase of the ionic conductivity. The successful application of this technique provides a new method to simultaneously investigate crystal structure and electrical properties in electro-ceramics in the future. 相似文献
7.
M. Laitinen T. Sajavaara T. Ishida 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(24):3021-3024
Atomic layer deposition (ALD) is currently a widespread method to grow conformal thin films with a sub-nm thickness control. By using ALD for nanolaminate oxides, it is possible to fine tune the electrical, optical and mechanical properties of thin films. In this study the elemental depth profiles and surface roughnesses were determined for Al2O3 + TiO2 nanolaminates with nominal single-layer thicknesses of 1, 2, 5, 10 and 20 nm and total thickness between 40 nm and 60 nm. The depth profiles were measured by means of a time-of-flight elastic recoil detection analysis (ToF-ERDA) spectrometer recently installed at the University of Jyväskylä. In TOF-E measurements 63Cu, 35Cl, 12C and 4He ions with energies ranging from 0.5 to 10 MeV, were used and depth profiles of the whole nanolaminate film could be analyzed down to 5 nm individual layer thickness. 相似文献
8.
为研究241Am在La2Zr2O7烧绿石中的固化行为及其对烧绿石晶体结构稳定性的影响,实验选用Nd作为241Am的模拟物,采用Sol-喷雾热解法合成了(La1-yNdy)2Zr2O7(0.0≤y≤1.0)系列样品,并借助X射线衍射和振动光谱手段对样品的晶体结构稳定性进行了研究。实验结果表明:随着Nd掺杂量的增加,O48f位置参数x48f和I(111) /I(222)均呈规律性增大,Raman谱逐渐展宽,IR谱发生蓝移,所有结果均证实用Nd不断替换La将导致烧绿石晶体结构有序化程度逐渐降低。另外,实验发现掺杂量y≈0.8是烧绿石晶体结构发生几何相变的逾渗阈值,超过该阈值有序的烧绿石结构将发生突变进而加速向无序萤石结构转变,该实验结果可为(La1-yAmy)2Zr2O7固溶体的结构稳定性研究提供参考。 相似文献
9.
A. Meftah W. AssmannN. Khalfaoui J.P. StoquertF. Studer M. ToulemondeC. Trautmann K.-O. Voss 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(9):955-958
The results of present paper have shown that sputtering of yttrium iron garnet (Y3Fe5O12) under swift heavy ions in the electronic energy loss regime is non-stoichiometric. Here we are presenting additional experimental results for gadolinium gallium garnet (Gd3Ga5O12) as target. The irradiations were performed with different ions (50Cr (589 MeV), 86Kr (195 MeV) and 181Ta (400 MeV)) impinging perpendicularly to the surface. As earlier, the sputtering yield was determined by collecting the emitted gadolinium and gallium atoms on a thin aluminium foil, placed upstream above the target and analyzing the Al catcher by Rutherford backscattering. Also for Gd3Ga5O12, the emission of Gd and Ga is non-stoichiometric. Sputtering appears above a critical electronic stopping power of Sth = 11.6 ± 1.5 keV/nm, which is larger than the threshold for track formation, in agreement with other amorphisable materials. In addition, the angular distribution of the sputtered species was measured for Y3Fe5O12 and Gd3Ga5O12 using 200 MeV Au ions impinging the surface at 20° relatively to the surface. For the two garnets the ratio of Y/Fe (and Gd/Ga) varies with the angle of emitted species and the stoichiometry seems to be preserved only for an emission perpendicular to the surface. 相似文献
10.
Bhushan Dhabekar S.N. MenonE. Alagu Raja A.K. BakshiA.K. Singh M.P. ChougaonkarY.S. Mayya 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(16):1844-1848
Optically Stimulated Luminescence (OSL) technique has emerged as a serious competitor to Thermally Stimulated Luminescence (TSL) technique in various dosimetric applications, especially after the development of crystalline alumina (Al2O3:C) doped with carbon. Since then, several attempts are being made to develop other possible materials for OSL based dosimetric applications. Efforts conducted in our laboratory in this direction have led to the development of a new phosphor, Lithium Magnesium Phosphate doped with terbium and boron (LiMgPO4:Tb,B). This phosphor is prepared by solid-state diffusion method involving conventional air furnaces with operating temperature 1000 °C and easily amenable to large scale production without compromising primary dosimetric advantages. In this work we present some of the dosimetric OSL characteristics of this phosphor. The phosphor exhibits a main TSL peak at 250 °C. The phosphor also emits OSL, when the irradiated phosphor is stimulated with 470 nm light with the OSL sensitivity 1.3 times that of commercially available Al2O3:C. Photoluminescence (PL) emission spectrum consists of sharp lines characteristics of Tb3+ emission. The OSL discs made out of this phosphor are reusable up to at least 50 cycles, the phosphor exhibits dose linearity up to 1 kGy. Minimum detectable dose is found to be 20 μGy and fading of the OSL signal is found to be about 16% in four days, after which the OSL signal stabilizes. 相似文献
11.
Jianrong Sun Zhiguang WangYuyu Wang Cunfeng YaoKongfang Wei Fashen Li 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(9):873-875
The effect of 2.03 GeV Kr26+ ions irradiation on antiphase boundaries (APBs) of polycrystalline Fe3O4 ferrite thin films has been investigated. The structure, magnetic and electrical transport properties of samples were characterized. The initial crystallographic structure of the Fe3O4 remains unaffected after Kr-ion irradiation, but the magnetic and electrical transports properties are sensitive to swift heavy ions (SHI) irradiation and exhibit different behaviors depending on the Kr-ion fluence range. The energy deposition is mainly due to the electronic energy loss (Se) and the large value of energy transferred induces an unusual density of defects, stress and heat annealing effect in the samples, which can affect on the arrangement of magnetic moments and APBs density strongly. On the basis of our observations we conclude that the production, accumulation and free of the defects and stress induced by SHI irradiation is more dominant in the case of the magnetic and electrical transport properties modifications of the Fe3O4 thin films. 相似文献
12.
Vacuum plasma etching of 1 wt% La2O3 doped tungsten alloy surfaces were carried out to refine the surface morphology for enhancing its bonding characteristics with copper for fusion reactor components. Three different gas compositions containing argon with zero, 14.3 and 25 vol% hydrogen were used to carry out the plasma etching from 30 to 120 s on the given samples. Mitutoyo surface roughness (Ra) measurement, FORM TALYSURF and scanning electron microscopy (SEM) were employed to measure the changes in the surface roughness. Plasma etching with 14.3 vol% hydrogen mixture was found to be the best in micro-roughening the alloy surface. The maximum increase of 44% in Ra value was obtained with this gas mixture, when etched for 90 s. 相似文献
13.
Numan Salah Zishan H. KhanSami S. Habib 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(4):401-404
Aluminum Oxide (Al2O3) doped with proper activators is a highly sensitive phosphor commonly used for radiation dosimetry using thermoluminescence (TL) technique. Nanoparticles of this material activated with Chromium (Cr) have been synthesized using the propellant chemical combustion technique and studied for their TL response. They were characterized by X-ray diffraction and scanning electron microscope. The synthesized material has spherical nanoparticles with grain size around 25 nm. These nanoparticles were exposed to heavy doses from γ-rays of 137Cs. The TL glow curves show a prominent peak at around 474 K. This peak is found to be sensitive for high exposures of γ-rays and has linear response in the range of 100 Gy-20 kGy without showing saturation. This remarkable result suggests that Al2O3:Cr nanoparticles might be used for the dosimetry of food and seed irradiations. 相似文献
14.
采用气相二氧化硅法制备了LaNi4.25Al0.75/SiO2复合材料。研究了该复合材料经不同温度(473~1 073 K)热处理后的相组成、形貌及吸放氢p-C-T曲线、吸氢动力学性能和吸放氢循环性能。结果表明,随着热处理温度的升高,LaNi4.25Al0.75/SiO2复合材料吸氢量减少,平台压升高,平台斜率略有增加,而动力学性能并无显著变化。经60次吸放氢循环后,经不同温度热处理后的样品均未出现粉化现象,且与未循环样品储氢性能基本保持一致。 相似文献
15.
R. Kumaravel K. Ramamurthi Indra Sulania K. Asokan 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(15):2391-2394
Transparent conducting cadmium stannate thin films were prepared by spray pyrolysis method on Corning substrate at a temperature of 525 °C. The prepared films are irradiated using 120 MeV swift Ag9+ ions for the fluence in the range 1 × 1012 to 1 × 1013 ions cm−2 and the structural, optical and electrical properties were studied. The intensity of the film decreases with increasing ion fluence and amorphization takes place at higher fluence (1 × 1013 ions cm−2). The transmittance of the films decreases with increasing ion fluence and also the band gap value decreases with increasing ion fluence. The resistivity of the film increased from 2.66 × 10−3 Ω cm (pristine) to 5.57 × 10−3 Ω cm for the film irradiated with 1 × 1013 ions cm−2. The mobility of the film decreased from 31 to 12 cm2/V s for the film irradiated with the fluence of 1 × 1013 ions cm−2. 相似文献
16.
《Journal of Nuclear Science and Technology》2013,50(11):1064-1068
HZr2(PO4)3 has been synthesized by the heat treatment of NH4Zr2(PO4)3 and its properties as an ion exchanger have been examined with the main focus on its alkali metal ion and lithium isotope selectivity. The distribution coefficients for alkali metal ions revealed that HZr2(PO4)3 was lithium ion-specific and showed little affinity toward potassium, rubidium or cesium ion. The lithium and sodium ion uptakes from aqueous solutions were monotonously increasing functions of pH. Isotopically, HZr2(PO4)3 was 6Li-specific. Contrary to ion uptake, the lithium isotope effect was a monotonously decreasing function of pH; a larger separation factor was observed at a lower pH. This result was consistent with the existence of two different ion exchange sites formed in lithium ion-inserted HZr2(PO4)3. 相似文献
17.
Tousif HussainR. Ahmad Nida KhalidZ.A. Umar A. Hussnain 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(18):1951-1955
A 2.3 kJ pulsed plasma focus device was used to prepare thin films of nc-(Ti,Al)N/a-Si3N4 at room temperature. The plasma focus device, fitted with copper anode encapsulated with Ti0.5Al0.5 anode, was operated with nitrogen as the filling gas. Films were deposited with various number of focus shots, at 90 mm from top of the anode and at zero angular position with respect to anode axis. XRD patterns show the growth of polycrystalline (Ti,Al)N thin films with orientations in the (1 1 1), (2 0 0), (2 2 0) and (3 1 1) crystallographic planes. Behavior of lattice constant, grain size and film roughness of deposited film as a function of variation in number of focus shots is discussed. SEM micrographs of film deposited with 15 number of focus shots exhibit well-developed net like structure of nc-(Ti,Al)N/a-Si3N4 and possibly nc-(Ti,Al)N/a-Si3N4/a-AlN or nc-TiN/a-Si3N4/a-AlN. Surface Roughness ranging 64 nm to 89 nm was also observed. 相似文献
18.
Kun Zhong Xiangqian Cheng Lu Yan Guoan Cheng 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(18):3114-3117
Silicon ions were implanted into SiO2 thin films with various doses and energies. For the films implanted with various ion doses the photoluminescence (PL) intensity of 470 nm firstly increased with the increase of Si ion dose, which is similar to the variation trend of displacement per atom (DPA) number during ion radiation. Further increasing Si ion dose the PL intensity of 470 nm decreased gradually since the neutral oxygen vacancy centers were destroyed. For the samples implanted with different energy the variation trend of PL intensity for 470 nm peak is similar to the result of DPA under different radiation energy according to SRIM2006 simulation. With the increase of radiation energy a new PL peak at 550 nm appeared because of the variation of defect type. Combining with the simulation results and PL spectra the radiation effect on Si/SiO2 thin films were proposed. 相似文献
19.
Oscar A. Restrepo Aneesh PrabhakaranArnaud Delcorte 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(14):1595-1599
Using molecular dynamics simulations (MD), this contribution compares the interaction of three energetic clusters (Au3, Au400 and C60) with a hybrid surface of crystalline polyethylene (PE) covered by a layer of gold nanoparticles. This model system mimics the situation encountered in metal-assisted secondary ion mass spectrometry. The chosen impact points are representative of the PE surface, the metal particles and the frontier between the metal and the polymer. The simulations show the differences between the impact over the Au nanoparticle and the polymer surface, in terms of projectile penetration, crater formation and sputtering yield of PE and gold species. For C60 and Au3 projectiles, a simple correlation is found between the quantity of energy deposited in the top polymeric layers and the quantity of sputtered polymer material, including all the impact points. The results obtained with Au400 do not fit on this line, indicating that other physical parameters are prevalent. The mechanistic view of the interaction provided by the MD helps explain the differences. In short, while C60 and Au3 quickly break apart, creating energetic recoils and severing many bonds in the surface, Au400, with the largest total momentum by far (∼10 times larger than the others) and the lowest energy per atom (25 eV), tends to act and implant in the solid as a single entity, pushing the polymeric material downwards and breaking few bonds in the surface. 相似文献
20.
X. Xiang M. Chen X.T. Zu Y. Zhang 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(9):1440-1445
Room-temperature Ti ion implantation and subsequent thermal annealing in N2 ambience have been used to fabricate the anatase and rutile structured N-doped TiO2 particles embedded in the surface region of fused silica. The Stopping and Range of Ions in Matter (SRIM) code simulation indicates a Gaussian distribution of implanted Ti, peaked at ∼75 nm with a full width at half maximum of ∼80 nm. However, the transmission electron microscopy image shows a much shallower distribution to depth of ∼70 nm. Significant sputtering loss of silica substrates has occurred during implantation. Nanoparticles with size of 10-20 nm in diameter have formed after implantation. X-ray photoelectron spectroscopy indicates the coexistence of TiO2 and metallic Ti in the as-implanted samples. Metallic Ti is oxidized to anatase TiO2 after annealing at 600 °C, while rutile TiO2 forms by phase transformation after annealing at 900 °C. At the same time, N-Ti-O, Ti-O-N and/or Ti-N-O linkages have formed in the lattice of TiO2. A red shift of 0.34 eV in the absorption edge is obtained for N-doped anatase TiO2 after annealing at 600 °C for 6 h. The absorbance increases in the ultraviolet and visible waveband. 相似文献