120keV的N+注入SiC薄膜的光谱特性研究

文中主要研究了120keV的N⁺注入后SiC薄膜样品的光致发光谱(PL)和傅立叶红外光谱(FTIR)特性.从红外光谱可以看到有明显得碳氮单键、双键、三键等新结构生成.从PL光谱则发现365nm处的发光峰明显增强,这表明N⁺注入使得带隙中深的能级辐射中心复合的效率大幅度提高     

Modification of Fe/Cu multilayers under 400 keV Xe20+ irradiation

Two kinds of Fe/Cu multilayers with different modulation wavelength were deposited on cleaved Si(100) substrates and then irradiated at room temperature using 400 keV Xe²⁰⁺ in a wide range of irradiation fluences. As a comparison, thermal annealing at 300—900℃ was also carried out in vacuum. Then the samples were analyzed by XRD and the evolution of crystallite structures induced by irradiation was investigated. The obtained XRD patterns showed that, with increase of the irradiation fluence, the peaks of Fe became weaker, the peaks related to Cu-based fcc solid solution and Fe-based bcc solid solution phase became visible and the former became strong gradually. This implied that the intermixing at the Fe/Cu interface induced by ion irradiation resulted in the formation of the new phases which could not be achieved by thermal annealing. The possible intermixing mechanism of Fe/Cu multilayers induced by energetic ion irradiation was briefly discussed.     

注入Ar+的蓝宝石晶体退火前后光致发光谱的分析

对注入Ar⁺后不同晶面取向的蓝宝石晶体在不同退火条件下的光致发光谱进行了分析.分析结果表明:三种晶面取向的蓝宝石样品经Ar⁺注入后,其光致发光谱中均出现了新的位于506nm处的发光峰;真空和空气气氛下的退火均对样品在506nm处的发光有增强作用,不同晶面取向的样品发光增强程度不同,且发光增强至最大时的退火温度也不同,空气气氛下的退火使样品发光增强程度更为显著.由此可以看出,退火气氛、退火温度和晶面取向均对样品发光峰强度有影响. 关键词： 2O₃')" href="#">Al₂O₃ 离子注入 退火 光致发光谱     

氮化碳薄膜的制备及研究现状

 氮化碳具有良好的物理、化学性质和广泛的应用前景。目前主要采用化学气相沉积法、离子束溅射法、激光等离子体沉积和激光烧蚀、离子镀、离子注入法等制备方法。文中对氮化碳的结构、性质、制备、性能表征以及研究现状进行了比较详细的介绍。     

高能重离子辐照的ODS铁素体钢脆化效应研究

与传统的铁素体钢相比,氧化物弥散强化(ODS) 的铁素体钢具有更优的耐高温和抗辐照性能,近年来成为先进核能装置重要的候选结构材料。在HIRFL 的扇聚焦型回旋加速器(SFC) 材料辐照终端,对一种氧化物弥散强化(ODS) 铁素体钢MA956 进行了高能Ne 离子辐照实验,旨在研究级联碰撞损伤和惰性气体原子注入条件下该材料力学性能的变化。利用辐照终端的能量衰减装置将SFC出口123.4 MeV的离子能量分解为介于38.5~121.0 MeV之间的30 个入射能量值,并通过双面辐照在厚度60 μm的样品中均匀产生了损伤。辐照剂量为9x1016 ions/cm2,在样品中的平均位移损伤为0.7 dpa,注入的Ne原子浓度为350 appm。辐照期间样品温度保持在440 ℃附近。对辐照前后的样品分别在室温和500 ℃下进行了小冲杆试验(Small-punchTest),获得了辐照前后样品的加载位移曲线,由此得到该辐照条件下样品的延性损失为18%~26%。通过扫描电子显微镜观察了断口形貌和厚度变化,估算了样品的等效断裂应变和断裂韧性。结果表明,MA956 钢经过高能Ne离子辐照后等延伸率减小,断裂韧性降低,样品发生了一定的脆化。透射电镜结果说明氧化物弥散相界面处微空洞的形成可能是导致脆化的原因。Oxide dispersion strengthened (ODS) ferritic steels have better high-temperature creep rupture strength and higher irradiation resistance than conventional ferritic steels, and show high prominence of application in advance nuclear reactors. Their stability under high-dose radiation conditions needs to be clarified. In the present study, a commercial ODS ferritic steel MA956 were irradiated with high 20Ne ions at a terminal chamber of the Sector-focused Cyclotron (SFC) at HIRFL (Heavy-ion Research Facility in Lanzhou). With the energy gradient degrader of the irradiation chamber, the primary energy (123.4 MeV) of the Ne-ion was dispersed into 30 different energies between 38.5~ 121.0 MeV, which resulted in a plateau distribution of lattice damage in the specimens. The specimens were irradiated from both sides so that the whole 60 m thickness was nearly uniformly damaged. The specimen temperature was maintained around 440 ℃ during the irradiation. The irradiation dose is about 9x1016 ions/cm2, corresponding to a damage level of 0.7 dpa and a Ne concentration of 350 appm. The specimens before and after irradiation were tested with the Small-punch Test technique, at room temperature and 500 ℃, respectively. The fracture morphology was observed by scanning electron microscopy.The results show that MA956 underwent some loss of ductility and fracture toughness after the irradiation with high-energy 20Ne ions. It may be ascribed to the formation of nano-scale cavities at the oxides/matrix interfacesin the ODS steel specimens under irradiation .     

56Fe13+离子引起GaP晶体的微结构损伤

利用X射线衍射（XRD）技术、傅里叶变换红外光谱（FTIR）和Raman光谱对经不同剂量的56Fe13+离子辐照的GaP晶体的微结构进行了表征。结果表明:随着辐照离子剂量的增加,GaP晶体中产生了局部的无序与缺陷。随着56Fe13+离子剂量的增加,Raman光谱展示出振动峰强度逐渐减弱而且一些逐渐消失,但其峰位几乎没有发生变化;XRD显示出GaP晶体的衍射峰的强度逐渐减小;FTIR主要表现为宽化及其强度增加。这表明重离子56Fe13+的辐照使得GaP晶体中的缺陷与无序性增加,导致晶体产生了局部的非晶化。The Misconstructural damage of GaP irradiated with 56Fe13+ to fluences ranging from 1×107 ions/cm2~1×1010 ions/cm2 were analyzed by X-ray diffraction (XRD) techniques, Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The result shows that, with the increase of irradiation ion fluences, local disorder and defects were produced in GaP crystal. With the increase of ion fluence, Raman spectra reveal the intensity of scattering peaks gradually weakens and some scattering peaks gradually disappear, however no changes in the peak position were found. XRD measurement displays that the intensity of diffraction peaks gradually decreases with an increase in ions fluences. Result from FTIR spectra exhibits that the intensity of reflection peaks gradually increases and the FWHM of reflection peaks broadens. These phenomena indicate that, the irradiation of heavy-ion Fe produces defects and disorder in GaP crystal, leading to a local amorphization.     

16Cr-ODS铁素体钢的初始氧化物弥散相结构对抗辐照硬化和Ne离子脆化性能的作用研究

依托兰州重离子研究装置(HIRFL),开展了3种不同氧化物弥散强化的16Cr-ODS铁素体钢的重离子辐照损伤研究,旨在探究氧化物颗粒结构参数(尺寸和密度)对材料辐照硬化和Ne离子辐照脆化效应的影响.采用6.17 MeV/u的Ni离子辐照和Ne离子,借助辐照终端的梯度减能装置在材料样品中产生了均匀的辐照损伤坪区.借助纳米...     

高能238U离子辐照AlN 晶体薄膜的光学特性研究

通过傅里叶变换红外光谱、拉曼光谱和光致发光谱测试手段分析了由HIRFL 提供的高能238U离子辐照AlN 晶体薄膜的光学特性变化。辐照后出现了A1(To),A1(Lo),E1(To) 和E2 等声子振动吸收模式,并且辐照使其在样品近表面Al—N 等振动模式遭到破坏后悬空的Al— 键很快与空气中的O离子发生结合,形成了Al—O 键。综合分析得出了蓝光发射带是与O 离子相关的VAl-ON-3N 和VAl-2ON-2N两种类型缺陷以及F-型缺陷聚合所致;绿光发射带是由基底中Al 原子产生的价带之间的跃迁所致。AlN thin film irradiated with 100 MeV 238U ions delivered from HIRFL (Heavy Ion Research Facility in Lanzhou) were investigated by Fourier Transform Infrared spectra, Raman spectra and Photoluminescence spectra. Phonon vibration absorption modes including A1(To), A1(Lo), E1(To) and E2 appeared in the irradiated samples. The irradiation made the Al—N bonds broken and the formation of Al—dangling bonds, which combined soon with oxygen atoms existing in air to form Al—O bonds. Blue light emission band are related to the two types of defects of VAl-ON-3N and VAl-2ON-2N and F-type defects aggregation. Green light emission band is due to energy transition among valence band of Al atoms in sapphire substrate.     

离子注入/辐照引起Al2O3单晶的改性研究

600K温度下用110keV的He^＋,Ne^＋,Ar^＋离子注入及320K温度下用230MeV的^208Pb^27＋辐照Al2O3单晶样品,研究了离子注入和辐照对Al2O3单晶样品结构和光学特性的影响。从测得的光致发光谱可以清楚地看到,所有样品在波长为375,413和450nm处出现了强的发光峰。且所有5×10^16ion／cm^2注入样品的发光峰均最强。经过高能Pb辐照后的样品,在390nm处出现了新的发光峰。透射电镜分析发现在注入氖样品100nm入射深度以内形成了高浓度的小空洞（1-2nm）,在Ne沉积区域有少量大空洞形成。傅立叶变换红外光谱分析发现,波数在460-510cm^-1间的振动吸收带经过离子辐照后展宽,随着辐照量的增大,该振动吸收强度显著减弱。1000—1300cm^-1对应Al-O-Al桥氧伸缩振动模式的吸收带,辐照后向高波数方向移动。对离子注入和辐照对Al2O3单晶样品结构损伤机理进行了初步探讨。Single crystal sapphire （Al2O3 ） samples were implanted at 600 K by He, Ne and Ar ions with energy of 110 keV to doses ranging from 5 × 10^16 to 2× 10^17 ion/cm^2 or irradiated at 320 K by ^208Pb^27＋ ion with energy of 1.1 MeV/u to the fluences ranging from 1 × 10^12 to 5 × 10^14 ion/cm^2. The modification of structure and optical properties induced by ion implantation or irradiation were analyzed by using photoluminescence（PL） and Fourier transformation infrared spectrum（FIR） spectra and transmission electron microscopy（ TEM ） measurements. The PL measurements showed that absorption peaks located at 375,413 and 450 nm appeared in all the implanted or irradiated samples, the PL intensities reached up to the maximum for the 5 × 10^16 ion/cm^2 implanted samples. After Pb-ion irradiation, a new peak located at 390 nm formed. TEM analyses showed that small size voids,（ 1--2 nm） with high density were formed in the region from the surface till to about 100 nm in depth and also large size Nebubble formed in the Ne-doped region. From the obtained FTIR spectra, it was found that Pb-ion irradiation induced broadening of the absorption band in 460-510 cm^-1 and position shift of the absorption band in 1 000- 1 300 cm^- 1 towards to high wavenumber. The possible damage mechanism in single crystal sapphire induced by energetic ion implantation or irradiation was briefly discussed.     

退火对He注入及随后208 Pb27+辐照的Al2O3单晶PL谱的影响

利用高能离子研究了110 keV的He+注入Al2O3单晶及随后230 MeV的208pb27+辐照并在不同温度条件下退火样品的光致发光的特性.从测试结果可以清楚地看到在375 nm,390 nm,413 nm和450 nm出现了强烈的发光峰.经过600 K退火2 h后测试结果显示,390 nm发光峰增强剧烈,而别的发光峰显示不明显.在900 K退火条件下,390 nm的发光峰开始减弱相反在510 nm出现了较强的发光峰,到1100 K退火完毕后390 nm的发光峰完全消失,而510 nm的发光峰相对增强.从辐照样品的FTIR谱中看到,波数在460-510 cm-1间的吸收是振动模式,经过离子辐照后,吸收带展宽,随着辐照量的增大,Al2O3振动吸收峰消失,说明Al2O3振动模式被完全破坏.1000-1300cm-1之间为Al-O-Al桥氧的伸缩振动模式,辐照后吸收带向高波数方向移动.退火后的FTIR谱变化不大.