钙长石中镓置换骨架铝对结构和Eu~(2+)发光特性的影响

采用高温固相法在弱还原气氛下制备了Ca0.955Al2-xGaxSi2O8∶Eu2+(x=0～1.0)系列荧光粉,研究了Ga3+置换Al3+对晶体结构和光谱特性的影响。Ga3+以类质同相替代CaAl2Si2O8晶格中的Al3+形成连续固溶体,晶胞参数a,b,c和晶胞体积V随Ga3+置换量呈线性增大;晶面夹角α,β和γ随Ga3+置换量的增加呈线性递减。荧光激发谱为宽带,位于230～420 nm,可拟合成4个峰,表观峰值位于352 nm;随着Ga3+置换量的增加,半高宽从112 nm减小到98 nm。发射光谱位于375～560 nm,可由421和457 nm两峰拟合而成,表观峰值位于425 nm,随着Ga3+置换量的增加,两拟合峰均线性红移,且拟合峰强度比呈线性递减。     

磁性形状记忆合金Ni50Mn29Ga21Tb1.2室温下的晶体结构研究

采用差热分析和X射线衍射及透射电子显微分析,研究了Ni50Mn29Ga21Tb1.2形状记忆合金的马氏体转变温度、室温下的马氏体的结构及亚结构.结果表明 Ni50Mn29Ga21Tb1.2室温下以体心四方结构的五层马氏体为主,其晶格常数为 a=b=0.60 nm,c=0.5546 nm;在某一微小区域内有体心斜方结构的七层马氏体,其晶格常数为 a=0.616 nm,b=0.581 nm,c=0.553 nm,β=90.8°;Ni50Mn29Ga21Tb1.2室温下的亚结构为孪晶.     

超晶格多层膜的电化学制备、表征及其GMR特性的研究

以半导体Si为衬底,电化学沉积Cu/Co超晶格多层膜,用SEM表征多层膜的断面形貌.XRD研究表明,多层膜的调制波长为20～160 nm时,膜层间发生外延生长.随着调制波长的减小,外延生长对膜层结构的影响越来越明显.当调制波长小于20 nm时,在XRD强衍射峰的两侧出现卫星峰,表明多层膜形成超晶格结构.根据卫星峰位置计算的调制波长与由法拉第定律估算的结果非常接近.多层膜的巨磁电阻(GMR)性能随多层膜周期数的增加而增大;当周期数大于300时,GMR性能基本上不再随周期数变化,说明基体的导电性质对GMR的影响可以忽略.     

利用X射线衍射考察不同缓冲层对AlGaN外延薄膜微结构的影响

为了获得高质量的高Al组分AlGaN外延材料,一般是在蓝宝石基片与外延层之间引入缓冲层或模板层（GaN、AlN或两者的交替周期超晶格）来提高AlGaN的外延质量,不同的缓冲层及结构对AlGaN的外延质量产生不同的影响.利用三轴晶高分辨X射线衍射（TAXRD）表征手段对2种生长结构下的AlGaN进行表征分析.     

Cu-12％Al合金熔体内中程有序原子团簇

通过高温X射线衍射仪研究了Cu 12％Al（质量分数,下同）合金熔体结构,并用纯铜作对比实验.在1250 ℃时,发现Cu 12％Al合金熔体结构因子曲线上18.5 nm－1位置有预峰出现.随着温度的下降,预峰变得更加明锐.预峰的出现是液体中存在中程有序的标志.通过熔态旋淬法获得该合金的快速凝固条带,对条带进行固态X射线衍射分析,其结构是具有有序体心立方晶格的Cu3Al.熔体内的中程有序结构单元尺寸与快凝Cu3Al（111）晶面面间距d111数值一致.由双体分布函数得到的最近邻原子距离、配位数.结合原子团簇结构单元的几何模型,计算得出该体心立方的棱边长(a=3.00 10－10m)与文献中所提供的固态晶格常数（a=2.95 10－10 m）基本吻合.可证明该合金熔体中存在以DO3结构为基本单元的中程有序原子团簇,在液相线以上200 ℃温度范围内这种中程有序都能稳定存在,并随着温度的下降,中程有序的相关尺寸逐渐增大.     

径向基函数神经网络荧光光度法同时测定痕量铝、镓、铟、铊

以径向基网络(RBF)对荧光光谱严重重叠的Al3 、Ga3 I、n3 、Tl3 四组分混合体系同时进行测定。通过正交设计安排样本,在激发波长390 nm下,测定446~615nm的发射光谱。以34个特征波长处的荧光强度值作为网络特征参数,经网络训练和计算得出Al3 、Ga3 、In3 、Tl3 四者的平均回收率分别为99.07%、103.49%、98.72%、95.04%,在时间和精度上都比LMBP网络优越。     

小角X射线散射研究乳胶分散液的微观结构

采用同步辐射小角X射线散射（SAXS）技术观察了2种不同乳胶体系的微观结构以及将其混合对结晶行为的影响。 结果表明,体积分数为50%的苯乙烯-丙烯酸丁酯共聚物乳胶液在室温下没有结晶。 通过对散射强度曲线的拟合,乳胶粒子的平均半径是76 nm,小于动态光散射的测量值（80 nm）。 然而,50%的苯乙烯-丁二烯共聚物乳胶液发生了结晶。 利用面心立方（fcc）结构和晶格常数为212 nm的晶格衍射进行拟合,发现散射曲线中的所有Bragg衍射峰均对应1个或多个晶面指数。 将2种乳胶液混合后各个衍射峰仍能分辨出来,这说明原始乳液中的部分微晶在混合过程中仍然稳定存在。     

低浓度HPAM/AlCit交联聚合物溶液性质研究

采用粘度法、扫描电镜（SEM）、核孔膜过滤、动态光散射（DLS）和27Al NMR法，研究了高分子量低浓度的部分水解聚丙烯酰胺（HPAM）与柠檬酸铝（AlCit）体系交联反应过程溶液性质变化.结果表明，HPAM与AlCit反应在低剪切速率时体系粘度随反应进行而降低，在剪切速率较高时具有剪切稠化现象，HPAM与AlCit反应过程中交联态Al的自旋 晶格弛豫时间随反应进行变短.低浓度的HPAM与AlCit发生分子内交联反应形成交联聚合物线团（LPC）在水中的分散体系，即交联聚合物溶液（LPS）.交联聚合物溶液中LPC的平均流体力学半径约为238 nm，其形态接近球形，具有多分散性. LPS对1.2 μm核孔膜的封堵程度与其反应时间有关.     

硼、铝和镓掺杂对硅纳米管电子结构和光电性质的影响

基于密度泛函理论的第一性原理计算,研究了本征硅纳米管（SiNTs）的几何结构,以及Ⅲ族元素B、Al、Ga掺杂对单壁锯齿型（14,0）SiNTs稳定性、电子结构和光学性质的影响。结果表明,褶皱型SiNTs为SiNTs稳定存在的结构,B、Al、Ga掺杂能够提高SiNTs的稳定性。本征（14,0）SiNTs属于窄带隙金属材料,通过B、Al、Ga的分别掺杂,SiNTs的带隙变宽,实现了SiNTs从金属性向半导体性质的转变。随着Ⅲ族元素原子序数的增大,其掺杂体系的稳定性不断降低,相应的带隙也不断减少。B、Al、Ga掺杂的单壁锯齿型（14,0）SiNTs具有近乎一致的光学性质,对于紫外光有着很强的吸收特性,并且对于红外和可见光吸收也有着不错的提升。     

具有可见光响应的C、N共掺杂TiO2纳米管光催化剂的制备（英文）

为了提高二氧化钛对可见光的利用效率,采用等离子体电解方法对二氧化钛实现了C、N共掺杂.掺杂通过等离子体电解HCONH2、NaNO2、（NH2）2CO产生活性N、C实现.XPS结果表明,C、N掺杂进入了氧化钛晶格.紫外漫反射光谱分析表明,氧化钛对可见光（〉400nm）的响应增强,其光催化降解能力也大大增强.C、N共掺杂TiO2是一种利用太阳能的理想的光催化剂.     

Growth of uniformly aligned ZnO nanowire heterojunction arrays on GaN, AlN, and Al0.5Ga0.5N substrates

Vertically aligned single-crystal ZnO nanorods have been successfully fabricated on semiconducting GaN, Al0.5Ga0.5N, and AlN substrates through a vapor-liquid-solid process. Near-perfect alignment was observed for all substrates without lateral growth. Room-temperature photoluminescence measurements revealed a strong luminescence peak at approximately 378 nm. This work demonstrates the possibility of growing heterojunction arrays of ZnO nanorods on AlxGa1-xN, which has a tunable band gap from 3.44 to 6.20 eV by changing the Al composition from 0 to 1, and opens a new channel for building vertically aligned heterojunction device arrays with tunable optical properties and the realization of a new class of nanoheterojunction devices.     

SUY的晶胞参数和骨架振动频率与其硅铝比间的关系

用SiCl₄(气)高温处理HY制得一系列USY(T),以USY(T)的晶胞常数α₀对其单位晶胞中铝原子的数目作图,发现c₀在24.45～24.55有一断落区间。由实验结果推导出两个以晶胞常数计算USY骨架硅铝比的公式。用400～1500cm^-1范围的红外光谱研究了USY的骨架变化。一些骨架振动特征频率与晶胞常数,单位晶胞中铝原子分数的相关图,也都出现断落区间。当晶胞常数小于24.41时,460cm^-1及1145cm^-1的两个峰发生劈裂。随晶胞常数的减少光谱峰变窄。     

Layered Double Hydroxides with Hydrotalcite—type Structure Containing Fe^3＋,Al^3＋ and Mg^2＋

IntroductionLayered double hydroxides( LDHs) with hy-drotalcite ( HT ) - type structure are composed oftrivalent and divalent metal ions and have the gen-eral formula[1] ,[M2 + 1-x M3 + x ( OH) 2 ]x+ An-x/ n· m H2 O,where M3 + is a trivalentmental ion,such as Al3 + ,Fe3 + ,La3 + ,Ni3 + ,Mn3 + etc.,M2 + is a divalentmetal ion,such as Mg2 + ,Zn2 + ,Ca2 + ,Cu2 + ,Co2 +etc.,An-is a charge compensating anion,such asOH-,Cl-,NO-3 ,CO2 -3 etc.,m is the number ofthe moles of co- intercalat…     

Origins for epitaxial order of sexiphenyl crystals on muscovite(001)

The epitaxial order of sexiphenyl crystals on muscovite(001) is investigated by x‐ray diffraction, lattice misfit calculations and atomic force microscopy. Depending on the substrate temperature during the thin film growth process, different epitaxial orientations are formed. Sexiphenyl thin films prepared at 370 K preferentially form crystals with the crystallographic (11‐1) planes parallel to the substrate surface while at 434 K a strong fraction of crystals with (11‐2) orientations is grown. The epitaxial orders of sexiphenyl crystals are compared with lattice misfit calculations. The in‐plane order of the {11‐1} crystals can be explained by a point‐on‐line coincidence I, which reveals that the interface is formed by undisturbed crystal surfaces. The epitaxial order of the {11‐2} oriented crystals is characterised by the experimental observation that low indexed crystal directions in the sexiphenyl(11‐2) plane and the muscovite(001) surface coincide with each other, forming a near‐coincidence case. Corrugations of the substrate surface are responsible for this second type of epitaxial order. Characteristic features in the thin film morphology could be correlated to the two observed epitaxial orientations of the sexiphenyl crystals. Copyright © 2009 John Wiley & Sons, Ltd.     

[Ni(C6H4N2)(CHC6H4O)2]配合物晶体结构及性质

The complex has been synthesized and characterized by spectroscopic techniques and single-crystal X-ray analysis. The crystal is orthorhombic ， space group P2₁2₁2₁ with a=1.6620(3)nm， b=1.7300(4)nm， c=0.5450(1)nm and Z=4. In the crystal lattice， the molecules create a two-dimensional network structure through hydrogen bonds. The C-H…O intermolecular hydrogen bonds connect the title complex to form layer super-molecular plane structure perpendicular to the axis b， with the layers stacked by the Van der Waals interaction. CCDC： 195309.     

Thickness-dependent phase transition of AlxGa1-xN thin films on strained GaN

We report our investigation of phase transition of AlxGa1-xN thin films on GaN made by employing first-principles calculations. A critical thickness of two AlGaN molecular layers is determined for the wurtzite-to-zinc blende structural transition under compressive strains, which is associated with the second-nearest-neighbor interaction of electron bonds. Higher AlN mole fractions are found to favor the phase transition because of strong push toward covalency of the Al-N bonds under strains. Electronic structure results show that, after the phase transition, the spontaneous and piezoelectric polarizations of the AlGaN films are significantly reduced.     

A study on crystalline residual stress of the iPP surface layer in Al/iPP/Al under the influence of microwave irradiation

The residual stress of the iPP surface layer in Al/iPP/Al under the influence of microwave irradiation was investigated by thin film (TF)‐X‐ray diffraction (XRD). Depending on the irradiation time, we calculated the macro residual stress, micro stress, and lattice static distortion stress. The results show that the macroscopic residual tensile stress of irradiated iPP samples dropped from about 12 MPa to 4 MPa. D₍₃₀₀₎ (the β crystal phase) becomes larger from about 4 to 10 nm as the irradiation time increased, and the β‐form iPP becomes more perfect. However, for theα‐form phase, D₍₁₁₀₎ remains almost stable. Moreover, the microscopic distortion coefficient ε₍₃₀₀₎ that decreases from approximately 0.03 to 0.018, becomes smaller than ε₍₁₁₀₎ parallel to the irradiation time, so the microscopic stress of the β‐crystal is decreased. In addition, the lattice static distortion energy of the α‐form greatly increases from 2 to 6 MPa, but the lattice static distortion energy of the β‐crystals remains constant at about 1.5 MPa and is much smaller than that of the α‐crystals at the same irradiation time. These calculated results are in good agreement with that of the crystallinity and order parameter of the β‐crystals of the TF‐XRD. The lattice distortion energy is a major portion of the plastic deformation, therefore, it suggests that the lattice static distortion energy is the main cause of α → β crystalline transformation. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3759–3765, 2004     

Crystal structure of novel compounds in the systems Zr-Cu-Al, Mo-Pd-Al and partial phase equilibria in the Mo-Pd-Al system

The crystal structures of three Al-rich compounds have been solved from X-ray single crystal diffractometry: τ(1)-MoPd(2-x)Al(8+x) (x = 0.067); τ(7)-Zr(Cu(1-x)Al(x))(12) (x = 0.514) and τ(9)-ZrCu(1-x)Al(4) (x = 0.144). τ(1)-MoPd(2-x)Al(8+x) adopts a unique structure type (space group Pbcm; lattice parameters a = 0.78153(2), b = 1.02643(3) and c = 0.86098(2) nm), which can be conceived as a superstructure of the Mo(Cu(x)Al(1-x))(6)Al(4) type. Whereas Mo-atoms occupy the 4d site, Pd(2) occupies the 4c site, Al and Pd(1) atoms randomly share the 4d position and the rest of the positions are fully occupied by Al. A B?rnighausen tree documents the crystallographic group-subgroup relation between the structure types of Mo(Cu(x)Al(1-x))(6)Al(4) and τ(1). τ(7)-Zr(Cu(1-x)Al(x))(12) (x = 0.514) has been confirmed to crystallize with the ThMn(12) type (space group I4/mmm; lattice parameters a = 0.85243(2) and c = 0.50862(3) nm). In total, 4 crystallographic sites were defined, out of which, Zr occupies site 2a, the 8f site is fully occupied by Cu, the 8i site is entirely occupied by Al, but the 8j site turned out to comprise a random mixture of Cu and Al atoms. The compound τ(9)-ZrCu(1-x)Al(4) (x = 0.144) crystallizes in a unique structure type (space group P4/nmm; lattice parameters a = 0.40275(3) and c = 1.17688(4) nm) which exhibits full atom order but a vacancy (14.4%) on the 2c site, shared with Cu atoms. τ(9)-ZrCu(1-x)Al(4) is a superstructure of Cu with an arrangement of three unit cells of Cu in the direction of the c-axis. A B?rnighausen tree documents this relationship. The ZrCu(1-x)Al(4) type (n = 3) is part of a series of structures which follow this building principle: Cu (n = 1), TiAl(3) (n = 2), τ(5)-TiNi(2-x)Al(5) (n = 4), HfGa(2) (n = 6) and Cu(3)Pd (n = 7). A partial isothermal section for the Al-rich part of the Mo-Pd-Al system at 860 °C has been established with two ternary compounds τ(1)-MoPd(2-x)Al(8+x) and τ(2) (unknown structure). The Vickers hardness (H(v)) for τ(1) was found to be 842 ± 40 MPa.     

Mg-Fe-LDHs纳米颗粒的合成及其阴离子交换容量的研究

采用液相共沉淀法合成了镁铁型层状双氢氧化物(简称Mg-Fe-LDHs)纳米颗粒,考察了粒子形貌、化学组成、晶体结构、阴离子交换容量及原料配比的影响.结果表明,所合成样品为片状纳米颗粒,化学组成与原料配比基本一致.在所研究的原料配比范围内,产品中n(Mg):n(Fe)在2:1～4:1范围内,产品具有水滑石层状六方晶系结构.随n(Mg):n(Fe)从2:1增大到4:1,粒径增大(从37.9nm增大到61.2nm),六方晶格参数a降低(变化范围为0.317～0.310nm),而六方晶格参数c增大(变化范围为2.380～2.412nm),层间距增大(从0.793nm增大到0.804nm),阴离子交换容量增大(从0.52mmol/g增大到1.28mmol/g).     

含锡AB_5型非化学计量贮氢合金Ⅰ.合金的结构

采用X射线衍射法研究了LaNi5 .1 5 ,La(NiSn) 5 .1 4 ,La(NiSnCo) 5 .1 2 ,La(NiSnMn) 5 .1 2 ,La(NiSnCoMnAl) 5 .1 0 5种AB5 型非化学计量贮氢合金的结构。发现主物相中并未产生第二物相 ,AB5 型贮氢合金中B原子数发生正偏移时 ,晶胞体积减小 ,当B侧含有取代元素时 ,这种变化更加明显。对于非化学计量贮氢合金而言 ,少量Sn取代Ni后 ,晶胞体积大大提高。Mn ,Co和Al的加入也会影响晶胞常数。Sn ,Co ,Mn ,Al均会降低贮氢合金放氢平台压力。