Fe-Al/Al2O3涂层表面氧化膜的掠入射X射线衍射研究

本文采用掠入射X射线衍射（GXRD）α-2θ扫描模式,进行了掠入射角α为0.1°～5°范围内Fe-Al/Al₂O₃阻氚涂层表面氧化膜的X射线衍射实验。结果表明,随α的增加,表面氧化膜中Al₂O₃相与Fe₃Al相对应的衍射峰强度绝对值增强;α的增加加深了分析区域的深度,引起Al₂O₃相的相对含量下降,导致Al₂O₃相对衍射峰强度降低。对Fe-Al/ Al₂O₃涂层表面氧化膜的掠入射X射线衍射而言,较佳的掠入射角是0.25°,此时对应Al₂O₃相的衍射峰相对强度最高。经比对PDF卡片,表面氧化膜相结构为暂态γ-Al₂O₃（200）。在此基础上建立了GXRD分析Fe-Al/ Al₂O₃涂层表面亚微米氧化膜的相结构组成的快速无损检测方法。     

双吡咯烷酮为核的联噻吩衍生物SMDPPEH薄膜热退火过程中微结构变化的实时表征

用旋涂法制备了双吡咯烷酮为核的联噻吩衍生物(Diketopyrrolopyrrole-containing Oligothiophene,SMDPPEH)薄膜,并采用紫外-吸收光谱和掠入射X射线衍射方法研究了热退火过程中的微结构变化。原位热退火的紫外-吸收光谱结果表明,100?C及以上时,第二个和第三个最大吸收峰发生蓝移。掠入射X射线衍射结果表明SMDPPEH薄膜在100?C左右退火时有相变产生,并且随退火温度升高,薄膜的结晶度在增大。相应处理后的SMDPPEH薄膜的紫外-吸收光谱和掠入射X射线衍射证明了SMDPPEH薄膜这个相变保留到了降温后的薄膜中。     

ZnO/α-Al_2O_3界面结构的掠入射X射线衍射研究

采用脉冲激光沉积(PLD)技术,以α-Al2O3(001)为衬底,在不同衬底温度下制备ZnO薄膜.利用X射线衍射(XRD)和同步辐射掠入射x射线衍射(GID)研究了薄膜的结晶性能和薄膜与衬底的界面结构.实验结果表明,在衬底温度较低(450℃)时,ZnO薄膜主要受衬底拉应力的作用,使界面处a方向的晶格常数增大;而在衬底温度较高(750℃)时,ZnO薄膜主要受衬底压应力的作用,使界面处a方向的晶格常数减小;在优化的衬底温度(650℃)下,ZnO薄膜受到的衬底应力较小,结晶性最好.且ZnO薄膜垂直方向的晶格排列要比面内的晶格排列更有序.     

同步辐射掠入射X射线衍射研究α相聚辛基芴薄膜的微结构

将旋涂制备的薄膜在120℃下退火,得到α相的聚辛基芴薄膜,用吸收光谱和荧光光谱进行了验证.用同步辐射一维和二维掠入射X射线衍射对薄膜进行了结构表征,结果表明,虽然聚辛基芴系非线型分子,但在薄膜微晶中分子链段主要以平行于基底的edge-on模式排列.     

Si（001）衬底自组织生长Ge量子点的组分和应变

利用同步辐射掠入射和常规X射线衍射，对Si(001）衬底上自组织生长Ge量子点组分和应变进行了研究。结果表明量子点为50％应变驰豫的GeSi合金量子点，其Ge组分为0．55。此外在掠入射X射线衍射Si(220）峰的高角旁观察到另外一个峰，对应于量子点周围衬底中由成岛引起的压应变。     

金属铀表面非平衡磁控溅射CrNx薄膜的XPS分析与腐蚀性能

金属铀的化学性质十分活泼,极易发生氧化腐蚀。为改善基体的抗腐蚀性能,采用非平衡磁控溅射离子镀技术在金属铀表面制备CrN_x薄膜。采用X射线衍射和X射线光电子能谱研究薄膜表面的物相结构和元素成分分布,采用极化曲线研究薄膜的抗腐蚀性能。结果表明,CrN_x薄膜具有较好的致密性和抗腐蚀性能。当氮分压较小时,生成的薄膜为Cr+CrN+Cr₂N混合相。在金属铀表面制备1层CrN_x薄膜后,其腐蚀电位增大约465 mV,腐蚀电流密度明显降低,有效改善了贫铀表面的抗腐蚀性能。     

溅射功率对磁控溅射制备Bi薄膜结构和性能的影响

采用直流磁控溅射方法在不同功率下制备了铋(Bi)薄膜,对薄膜的沉积速率、表面形貌、生长模式、晶体结构进行了研究,并对其晶粒尺寸和应力的变化规律进行了分析。扫描电镜(SEM)图像显示：薄膜均为柱状生长,平均晶粒尺寸随溅射功率先增大后减小,薄膜的致密度随着功率的增加而降低,在60W时又变得较致密。X射线衍射(XRD)结果表明：Bi薄膜均为多晶斜六方结构,薄膜内应力随功率的增加由张应力变为压应力。     

Y2-x-yBixEuyMgTiO6荧光粉的发光特性研究

双钙钛矿因其结构灵活、易于掺杂、热稳定性好等优点,成为近几年的研究热点。稀土掺杂双钙钛矿基质材料的光致发光研究常见报道,但和热释光有关的研究较少。本文采用高温固相法合成了Bi³⁺和Eu³⁺共掺的Y_2-x-yBi_xEu_yMgTi O₆(0≤x<1,0≤y<1)系列样品,并测量了样品的X射线衍射谱(X-ray Diffraction,XRD)、光致发光光谱(Photoluminescence,PL)和热释光谱(Thermoluminescence,TL)。XRD分析表明：样品的晶体结构均为单斜晶系P2₁/n,Bi³⁺和Eu³⁺通过替代Y³⁺而掺入Y₂Mg Ti O₆中;PL表明：样品最佳掺杂浓度为x=0.01、y=0.20,该样品在620 nm附近有较强的红光发射(对应Eu³⁺的⁵     

La0.7Ca0.3MnO3薄膜的掠入射X射线衍射研究

利用90°离轴射频磁控溅射方法将Lao.7Ca0.3MnO3(LCMO)沉积于(001)取向的SrTiO3(STO)、MgO和α-Al2O3(ALO)单晶基片上,薄膜厚度均为500 A.通过掠入射X射线衍射技术测量了LCMO薄膜的横向晶格常数(即面内晶格常数),结合常规X射线衍射研究了LCMO薄膜的晶格应变及其弛豫情况.结果表明,LCMO薄膜在MgO和ALO基片上的应变弛豫临界厚度很小,这可能与薄膜-基片之间高的晶格失配率有关.LCMO薄膜的应变弛豫与四方畸变的弛豫可能具有不同的机制.利用掠入射X射线衍射对LCMO薄膜面内生长取向的研究给出了与利用电子显微技术研究相同的结果.     

11-巯基十一烷酸包裹的金纳米颗粒薄膜的二次电子发射

采用改进的Peterk合成法合成11-巯基十一烷酸(Mercaptoundecanoic Acid,MUA)包覆的金纳米颗粒。通过调控MUA与氯金酸质量比,得到分布均匀且稳定性较好的不同粒径(3 nm)的纳米金颗粒前驱体溶液,进而滴加该溶液形成薄膜。扫描电子显微镜(Scanning Electron Microscope,SEM)观测到薄膜中具有大量微米级的块状集团。同步辐射掠入射X射线衍射(Grazing Incidence X-ray Diffraction,GIXRD)揭示其具有面外长程有序的超晶格结构;X射线光电子谱(X-ray Photoelectron Spectroscopy,XPS)证实薄膜中Au-S键的形成。通过紫外光电子能谱(Ultraviolet Photoelectron Spectroscopy,UPS)进一步发现常温下1.5 nm粒径的薄膜具有比单晶金样品强10倍的优异二次电子发射能力,且发射峰半高宽是单晶金样品的1/4。本研究表明,MUA包覆的金纳米薄膜在电子发射源以及光电探测上具有应用前景。     

Microwave Plasma Chemical Vapor Deposition of Diamond Films on Silicon From Ethanol and Hydrogen

Diamond films with very smooth surface and good optical quality have been deposited onto silicon substrate using microwave plasma chemical vapor deposition(MPCVD)from a gas mixture of ethanol and hydrogen at a low substrate temperature of 450℃.The effects of the substrate temperature on the diamond nucleation and the morphology of the diamond film have been investigated and observed with scanning electron microscopy(SEM).The microstructure and the phase of the film have been characterized using Raman spectroscopy and X-ray diffraction(XRD).The diamond nucleation density significantly decreases with the increasing of the substrate temperature.There are only sparse nuclei when the substrate temperature is higher than 800℃ although the ethanol concentration in hydrogen is very high.That the characteristic diamond peak in the Raman spectrum of a diamond film prepared at a low substrate temperature of 450℃ extends into broadban indicates that the film is of nanophase.No graphite peak appeared in the XRD pattern confirms that the film is mainly composed of SP^3 carbon.The diamond peak in the XRD pattern also broadens due to the nanocrystalline of the film.     

Annealing behavior of ultrathin Mo layer located at interface or on surface of Ti－Si system

Annealing behavior,at different annealing temperatures,of an ultrathin Mo layer located between a Ti film and Si substrate or deposited on the top of surface of a Ti film was investigated by Rutherford backscattering spectrometry(RBS), cross-sectional transmission electron microscopy(TEM) and energy dispersive X-ray spectrometry(EDS),In a Ti/Mo/Si structure,partially reacted film with layer structure of Ti-rich silicide/TiSi2/(Mo,Ti) Si2 on a Si substrate was formed after 550℃ annealing for 30min.The ratio of Mo to Ti in(Mo,Ti)Si2 layer decreases from near Si substrate upwards and becomes zero at about 20nm away.In a Mo/Ti/Si structure, The surface Mo layer enhances the Si diffusion from the substrate during annealing.Mo bearing Ti rich silicide exists on the surface until 600℃ and then converts to (Mo,Ti )Si2 after 650℃ annealing,and the atomic ratio of Mo to Ti decreases from the top surface into Ti silicide film,and becomes zero at about 30nm away from the surface.In both cases of interface Mo and surface Mo layer,thd atomic ratio of Mo to Ti in the region of (Mo,Ti)Si2 was found to be very low,with an average value of less than 0.2.Low content of Mo in Mo containing ternary silicide leads easily to the formation of the stable phase of C54(Mo,Ti)Si2,which acts as a template for the formation of C54 TiSi2 beneath when Mo is deposited on the surface.     

衬底材料及基底温度对Sc膜形貌、结构的影响

在不同基底温度下,用电子束蒸镀法在未抛光Mo、抛光Mo及Si〈111〉基片上制备了Sc膜,并用XRD、SEM及AFM对薄膜的微观结构和表面形貌进行了分析测试。结果表明：衬底材料、基底温度对Sc膜结构、形貌的影响极大。物相结构相同的Mo基底,抛光Mo上的Sc膜表面较平整,倾向于混合生长;而粗糙Mo基底上Sc膜凸凹不平,为岛状生长。提高基底温度有利于抛光Mo基底上Sc膜的(002)方向择优生长,但高温时会导致Si基底上膜表面的物相由单质Sc变为ScSi化合物,作为吸氢材料,ScSi化合物的形成不利于吸氢,应尽量避免其生成。     

贮氢金属多层膜制备技术及吸氢性能研究

研究了用电子束蒸发方法在Mo底衬上制备Ti-Ni复合膜和在SiO2底衬上制备Mo-Ti-Ni复合膜的方法,用离子束分析方法测量了各膜层的厚度,并对样品的吸氢性能进行了分析。研究发现,Ti膜表面镀Ni后,其吸氢温度降低,吸氢总量增加,表明其吸氢活性增强;Mo-Ti-Ni复合膜在Ti氢化后与SiO2底衬结合良好,并具有较高的强度,但这种膜对底衬的清洁度要求更高;50nm的Ti膜难以吸氢,原因可能是膜制备过程中温度过高,导致Mo-Ti-Ni之间扩散加深,形成相对过厚的过渡层,这还需进一步研究。     

离子束增强沉积法制备Mo2N和Mo2-xTixN薄膜及其结构与性能研究

分别采用氮离子束增强沉积和Ｎ－Ｔｉ离子束同步增强沉积工艺制备了Ｍｏ２Ｎ和Ｍｏ２－ｘＴｉｘＮ薄膜，用ＸＲＤ，ＴＥＭ、划痕和阳极极化方法研究了两者的结构与性能。     

XRD investigation of the strain/stress state of ion-irradiated crystals

In this work, it is demonstrated that XRD is a powerful technique for the study of ion-irradiated materials. For this purpose, XRD experiments have been performed under different configurations on a 〈1 0 0〉-oriented yttria-stabilized zirconia single crystal implanted with 300 keV caesium-ions at 3 × 10¹⁴ cm⁻². Initially, it is demonstrated that the depth strain profile can be determined from the refinement of a symmetric θ-2θ scan. Moreover, in order to explore the whole XRD data, a model that describes the strain/stress state of the damaged layer is proposed. This model takes into account the elastic response of the bulk material (substrate) underneath the irradiated layer. The measured elastic strain is then the sum of a free strain due to the formation of radiation-induced defects and of an additional strain arising from the substrate elastic reaction. Application of this model allowed the calculation of the different strain contributions and the stress experienced by the irradiated layer. It is shown that these parameters may reach large values (respectively 0.7% and −1.9 GPa) despite the low radiation damage level.     

2219铝合金搅拌摩擦焊和钨极保护焊焊接件残余应力的中子衍射研究

利用中子衍射法对2219铝合金搅拌摩擦焊（FSW）和钨极保护焊（TIG）焊接件开展了三维残余应力测量，并对残余应力分布规律进行了分析。结果表明：焊接件的纵向残余应力数值较大；FSW焊接件残余应力整体较TIG焊接件的小；FSW和TIG焊接件的残余拉应力最大值分别为101 MPa和174 MPa，FSW焊接件残余拉应力最大值较TIG焊接件的小；FSW残余拉应力最大值处于轴肩边缘，且前进侧峰值大于后退侧峰值；TIG焊接件残余拉应力最大值处于焊缝边缘。通过中子衍射实验获得的焊接件残余应力分布，将可用于焊接工艺的优化与焊接件的寿命预测。     

衬底温度对蒸汽辅助沉积法制备钙钛矿薄膜微观结构的影响

通过调控薄膜生长衬底温度,提出了一种改良的蒸汽辅助沉积法制备有机-无机混合钙钛矿薄膜,可以更为可控优化薄膜生长条件。用同步辐射掠入射X射线衍射(Grazing Incidence X-ray Diffraction,GIXRD)结合扫描电镜(Scanning Electron Microscope,SEM)、紫外可见吸收谱(UV-Visible Absorption Spectrum)等表征方法证明衬底温度对制备的钙钛矿薄膜质量具有重要的作用:较低的衬底温度(约70?C)有助于钙钛矿晶粒的形成,其结晶性、晶面择优生长取向均较好,同时具有较高的光吸收性能;当衬底温度升高时(100?C、125?C),所制备的钙钛矿薄膜结晶性变弱,晶体择优生长取向明显变差,光吸收性能随之下降。研究结果有助于进一步优化蒸汽辅助沉积法制备钙钛矿薄膜工艺。