Co-Ni合金纳米线有序阵列的制备与磁性研究

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Determination of the Gamow–Teller strength function for the neutron-deficient isotopes In

The Gamow–Teller β decays of the neutron-deficient indium isotopes ^104–107In have been investigated by using total absorption γ-ray spectrometry on mass-separated sources. The experimental Gamow–Teller strength, deduced as a function of the excitation energy in the daughter nuclei ^104–107Cd, is compared to shell-model predictions.     

XANES/EPR Evidence of the Oxidation of Nickel(II) Quinolinylpropioamide and Its Application in Csp3−H Functionalization

An in situ generated oxidation species of nickel quinolinylpropioamide intermediate was produced. Characterization by X-ray absorption near edge structure (XANES) and EPR provides complementary insights into this oxidized nickel species. With aliphatic amides and isocyanides as substrates, a nickel-catalyzed facile synthesis of structurally diverse five-membered lactams could be achieved.     

Improved photoelectrochemical hydrogen production over decorated titania with copper and nickel oxides by optimizing the photoanode and reaction characteristics

We optimized photocatalytic hydrogen production over TiO₂-based photocatalyst by varying the dopant (nickel and copper oxide), thin film active area, nature and concentration of sacrificial agents, and light intensity in a photoelectrochemical (PEC) cell/dye-sensitized solar cell (DSSC). Various characterization techniques have been used to investigate the structural, morphological, optical, and PEC behavior of single and codoped TiO₂. The TiO₂ decorated with both Cu and Ni oxides with active area of 1 cm² in a mixture of 5 vol % glycerol and 1 M KOH under light intensity of 100 mWcm^?2 produced the maximum hydrogen of 338.4 μmol cm^?2 for 2 h. The superior photocatalyst performance of this photocatalyst is attributed to its small crystallite size and large pore size, as confirmed by X-ray diffractometer, Transmission electron microscopy (TEM), and surface area of Brunauer-Emmet-Teller (S_BET). The absorption edges of this photocatalyst had the highest red shift compared with single doped and pure TiO₂ because of more indirect transitions of the photoexcited electrons, greater charge carrier separation, and lower recombination rate. The photoanode active area of 1 cm² with better photocatalytic performance correlated with the number of defects and grain boundaries. Glycerol shifted the conduction band of the photocatalyst to more negative flat potential compared with others. Increasing the concentration of glycerol further than 5 vol% saturated the photocatalyst active sites, increased photooxidation intermediates of glycerol, and reduced the hydrogen production. The light intensity had the maximum impact on the hydrogen production and could strongly control the number of charge carriers in both the PEC cell and the DSSC.     

Ni/Ag Schottky contacts on Al0.11Ga0.89N grown on Si (1 1 1) substrate by plasma-assisted MBE

Al_0.11Ga_0.89N/GaN samples are grown by plasma-assisted molecular beam epitaxy method on (1 1 1) silicon substrates. High purity gallium (7N) and aluminum (6N5) were used to grow Al_0.11Ga_0.89N, GaN, and AlN, respectively. The surface morphology, structural and optical properties of the sample has been investigated by scanning electron microscope (SEM), and high-resolution X-ray diffraction (HR-XRD), respectively. HR-XRD measurement showed that the sample has a typical diffraction pattern of hexagonal Al_0.11Ga_0.89N/GaN heterostructures. Ni/Ag bilayers are deposited on Al_0.11Ga_0.89N as the Schottky contacts. The effect of annealing in oxygen ambient on the electrical properties of Ni/Ag/Al_0.11Ga_0.89N is studied by current–voltage measurement. The annealing at a temperature of 700 °C for 10?min results in an increase in the ideality factor from 1.033 to 1.042 and an increase in the Schottky barrier height from 0.708 to 0.811 eV. Furthermore, the annealing in oxygen ambient also leads to an increase in the surface roughness of the contacts from 0.0098 to 0.1360 μm which is in agreement with the SEM results.     

Ni/SnO_2复合薄膜的制备与光电性能

采用旋涂法将溶胶-凝胶法制备的Ni/Sn O2凝胶在玻璃基底上镀膜,得到了Ni/Sn O2复合薄膜,探讨了镍掺杂量、煅烧温度对薄膜结构和形貌的影响。通过X射线衍射、红外光谱、扫描电子显微镜等测试手段对Ni/Sn O2复合膜的结构和形貌进行表征。结果显示,500℃下煅烧的薄膜样品的结晶度较高,粒径小,颗粒分布均匀。用紫外-可见分光光度计和四探针电阻仪对其进行光学、电学性能测试,结果显示:适量的Ni掺杂可以提高Sn O2薄膜在近紫外光区的吸收,Ni/Sn O2薄膜在近紫外光区的吸收随着Ni2+掺杂摩尔分数从5%增加到10%而逐渐减小。当Ni2+掺杂摩尔分数为6%时,Ni/Sn O2复合薄膜的导电性能最好。     

Extended X‐ray absorption fine structure and multiple‐scattering simulation of nickel dithiolene complexes Ni[S2C2(CF3)2]2n (n = −2, −1, 0) and an olefin adduct Ni[S2C2(CF3)2]2(1‐hexene)

A series of Ni dithiolene complexes Ni[S₂C₂(CF₃)]₂ⁿ (n = ?2, ?1, 0) ( 1 , 2 , 3 ) and a 1‐hexene adduct Ni[S₂C₂(CF₃)₂]₂(C₆H₁₂) ( 4 ) have been examined by Ni K‐edge X‐ray absorption near‐edge structure (XANES) and extended X‐ray absorption fine‐structure (EXAFS) spectroscopies. Ni XANES for 1 – 3 reveals clear pre‐edge features and approximately +0.7 eV shift in the Ni K‐edge position for `one‐electron' oxidation. EXAFS simulation shows that the Ni—S bond distances for 1 , 2 and 3 (2.11–2.16 Å) are within the typical values for square planar complexes and decrease by ～0.022 Å for each `one‐electron' oxidation. The changes in Ni K‐edge energy positions and Ni—S distances are consistent with the `non‐innocent' character of the dithiolene ligand. The Ni—C interactions at ～3.0 Å are analyzed and the multiple‐scattering parameters are also determined, leading to a better simulation for the overall EXAFS spectra. The 1‐hexene adduct 4 presents no pre‐edge feature, and its Ni K‐edge position shifts by ?0.8 eV in comparison with its starting dithiolene complex 3 . Consistently, EXAFS also showed that the Ni—S distances in 4 elongate by ～0.046 Å in comparison with 3 . The evidence confirms that the neutral complex is `reduced' upon addition of olefin, presumably by olefin donating the π‐electron density to the LUMO of 3 as suggested by UV/visible spectroscopy in the literature.     

The saturation scale and its x-dependence from Λ polarization studies

The transverse polarization of forward Λ   hyperons produced in high-energy p–A$p\text{–}A$ collisions is expected to display an extremum at a transverse momentum around the saturation scale. This was first observed within the context of the McLerran–Venugopalan model which has an x  -independent saturation scale. The extremum arises due to the kt$k_t$-odd nature of the polarization-dependent fragmentation function, which probes approximately the derivative of the dipole scattering amplitude. The amplitude changes most strongly around the saturation scale, resulting in a peak in the polarization. We find that the observation also extends to the more realistic case in which the saturation scale Qs$Q_s$ is x-dependent. Since a range of x   and therefore Qs$Q_s$ values is probed at a given transverse momentum and rapidity, this result is a priori not expected. Moreover, the measurement of Λ   polarization over a range of xF$x_F$ values actually provides a direct probe of the x-dependence of the saturation scale. This novel feature is demonstrated for typical LHC kinematics and for several phenomenological models of the dipole scattering amplitude. We show that although the measurement will be challenging, it may be feasible at LHC. The situation at RHIC is not favorable, because the peak will likely be at too low transverse momentum of the Λ to be a trustworthy measure of the saturation scale.     

Theoretical study on the phase stability,elasticity, hardness and electronic structures of Ni–P compounds

A systematic investigation concerned with phase stability, elastic properties, hardness and relevant electronic structure of Ni–P compounds (Ni₃P, Ni₁₂P₅, Ni₂P, Ni₅P₄, NiP, NiP₂ and NiP₃) was carried out using first principles calculations. The calculated results show that the Ni–P compounds have strong hardness, ranging from 7.80–14.54 GPa. Also, the hardness values gradually increase with the P content. Electronic structure analysis shows that the strong Ni–P and part of P–P hybrid orbitals play important roles in the hardness of these compounds. The calculated elastic constants indicated that the Ni₃P, Ni₁₂P₅ and NiP₂ phases are significantly anisotropic, the NiP and Ni₂P exhibit some anisotropy, while the Ni₅P₄ and NiP₃ show a relatively isotropic character. At last, the properties of these Ni–P compounds including lattice constants, thermodynamic stability, elastic constants C_ij, bulk modulus B, shear modulus G, Young's modulus E and Poisson's ratio ν have been calculated.     

高择优锌-镍合金电沉积的现场ECSTM研究

采用"二步包封"法制备了性能良好的电化学STM针尖.以此为基础采用ECSTM现场研究了工艺条件下HOPG上高择优锌-镍合金的电沉积过程.研究结果表明这种高择优沉积层以侧向生长方式生长,而表面上电化学活性差的晶面构成了晶体生长过程的保留面,从而进一步形成了与基底表面方向一致的高择优沉积层,X射线研究表明这一择优面为(100)晶面.