K-Einfang der Silberisotope Ag110 und Ag108

K-electron capture of Ag¹¹⁰ has been observed for the first time using scintillation spectrometers in anticoincidence technique. The ratio of electron capture toβ ^?-decay was determined to (0.3±0.06)%.K-electron capture of Ag¹⁰⁸ has been remeasured with better accuracy, yielding a relative frequency of (1.73±0.12)% for the capture transition to the ground state of Pd¹⁰⁸.     

Preparation of high quality Ag film from Ag nanoparticles

A simple route to the high quality Ag film was developed at room temperature by using Ag nanoparticles stabilized by polyvinylpyrrolidone (PVP) as Ag source. The scanning electron microscopy (SEM) images indicate that the silver film prepared on the quartz substrate is smooth and dense. Meanwhile, the X-ray diffraction (XRD) of the film shows a face-centered cubic (fcc) phase of Ag.     

High-resolution photoemission from Ag(100), Ag(110), and Ag(111)

Energy distribution curves of photoelectrons emitted normal to (100), (110), and (111) faces of silver have been obtained at photon energies of 21.22, 16.85, and 11.83 eV. The results are compared with Christensen's relativistic band structure calculation of bulk silver yielding a close correspondence between experiment and theory. A surface state in the L gap immediately below the Fermi level is identified.     

The decay of 1.2 min Ag and 5.3 h Ag

The decay schemes of 1.2 min and 5.3 h ¹¹³Ag have been studied using Ge(Li) and NaI(Tl) detectors and a 4096-channel multiparameter pulse-height analyser system. The decay of 5.3 h ¹¹³Ag was found to involve 15 γ-rays and to produce 10 excited states in ¹¹³Cd at energies of 264.7, 298.0, 315.6, 583.9, 604.6, 681.1, 883.6, 936.9, 989.0 and 1195.2 keV. The italicized energies refer to negative parity states, through which 1.3% of the decays go to yield the isomer at 264.7 keV. The 604.6 keV level is thought to be a case|9/2⁻ level similar for those found in several odd-mass Te and Xe isotopes. The 1.2 min ^113mAg decay was found to populate several of the same levels in Cd and two additional levels at 452 and 689 keV. The 1.2 min ¹¹³Ag is the upper isomer with high spin, probably .     

The decay of neutron deficient97Ag,98Ag,and99g,m Ag

The decays of neutron-deficient 21-sec⁹⁷Ag, 44.5-sec⁹⁸Ag, 15-sec^99mAg, and 124-sec^99gAg nuclides have been investigated with the LISOL facility. Sources were produced by the⁹²Mo(¹⁴N, ypxn) reactions on an enriched⁹²Mo target. Positron-, x-, and γ-ray singles spectra have been performed on mass separated samples. The results are consistent with 9/2⁺ ground state in⁹⁹Ag and a high (6⁺ or 7⁺) spin and parity for⁹⁸Ag.     

Der Zerfall des Ag106g und Ag106m

The decays of the 25 min-Ag^106g and 8.3 d-Ag^106m have been investigated using Ge(Li)- and Si(Li)-counters. Theγ-rays of 17 transitions in the Ag^106g -decay and of 42 transitions in the Ag^106m -decay have been observed and their energies and relative intensities have been determined. The intensities of theseγ-rays and the intensities of conversion-electrons known from earlier measurements allow the determination ofK-conversion-coefficients for 23 transitions. The present data are consistent with a level-scheme of Pd¹⁰⁶ having states at 0, 0⁺; 511.8, 2⁺; 1127.8, 2⁺; 1133.1, 0⁺; 1228.8, 4⁺; 1557.4, 3⁺; 1562, 2⁺; 1702.8, 4⁺; 1931.7, 3, 4⁺; 2002, 0⁺; 2040.4, 3, 4⁺; 2076.8, 3, 4⁺; 2084.2, 3^?; 2305.7, 4^?; 2324, 1, 2⁺; 2350.4, 3, 4⁺; 2365.3, 3, 4⁺; 2529, 1, 2⁺; 2756.3, 5⁺; 2951.3 keV, 5⁺. The level-scheme of Pd¹⁰⁶ is compared with the predictions of the vibrational model for spherical nuclei.     

Strain distributions of confined Au/Ag and Ag/Au nanoparticles

The strain distributions of Au/Ag and Ag/Au nanoparticles confined in the Al2O3 matrix with different core sizes are investigated by using the finite element method, respectively. The simulation results clearly indicate that the compressive strains exerted on the Au/Ag and Ag/Au nanoparticles can be induced by the Al2O3 matrix. Moreover, it can be found that the strain gradient existing in a Au/Ag nanoparticle is much larger than that in a Ag/Au nanoparticle, which could be due to the larger Young's modulus of Au than that of Ag. With the core size increasing, the strain gradient existing in the Au/Ag nanoparticle becomes larger, while the strain gradient existing in the Ag/Au nanoparticle keeps constant. These different strain distributions may have significant influences on the structures and morphologies of the Au/Ag and Ag/Au nanoparticles, leading to the different physical properties for potential applications.     

Piezoreflectivity in Ag films

The changes in the dielectric constant of Ag films 1000 Å thick, in a direction parallel and perpendicular to the film, have been computed from piezoreflectance spectra measured at an angle of incidence of 45° and light polarized s and p. The results are compared to those computed for crystallites. They are interpreted in terms of band structure.     

Determination of interlayer diffusion parameters for Ag/Ag(111)

It is well known that the Ag/Ag(111) epitaxial system grows three dimensionally because of the existence of a relatively high excess diffusion barrier, DeltaE(s) = 0.13 eV, at the step edges. Several experimental methods have been developed to measure the step edge barrier in this system over a wide coverage range. The probability for an atom to move from a higher to a lower layer depends on both the barrier and the prefactor, so it is important to test whether the prefactors for hopping over a step, nu(s), and for hopping on a terrace, nu(t), are different. We present the results from several experiments on Ag/Ag(111) to conclude that nu(s)/nu(t) = 10(2.0+/-0. 3).     

The decay of Ag

The γ-radiation following the decay of ¹¹²Ag has been studied with a Ge(Li) detector. A total of 76 γ-rays was observed. The γ-γ coincidence and angular correlation relations involving the 617 keV 2⁺-0⁺ transition have been measured using Ge(Li)-NaI(Tl) and NaI(Tl)-NaI(Tl) detectors. These results have been used to confirm spins and parities of some levels of ¹¹²Cd in the proposed decay scheme. Cross sections for ¹¹²Ag production by ¹¹⁵In(n,α) and ¹¹²Cd(n, p) reactions have been measured; the ¹¹²Ag half-life has been determined as 3.14 ± 0.02 h.     

РАСПАД Ag108m

The -spectrum of the long-living isomer of Ag¹⁰⁸ (T_1/25 years) was studied by means of Ge(Li) semiconductor detectors. Eight gamma transitions were found with energies of 79.5, 405.7, 433.7, 613.5, 633.0, 722.6, 836.5 and 1020 keV and correspanding relative intensities of 0.083, 0.008,1, 1.05, 0.0018,1.02,0.0006 and 0.010. The conversion coefficients and multipolarities were determined for transitions of 79.5, 613.5 and 722.6 keV. In the decay scheme of Ag^108m the sequence of the levels 4⁺ (1047 keV) and 0⁺ (1049 keV) is given and the existence of the levels 1454 keV and 1469 keV is confirmed. Spin and parity 2^– were ascribed to the 80 keV level of Ag¹⁰⁸ on the basis of the multipolarity of the 79.5 keV transition.     

Ag/Fe/Ag 纳米颗粒膜磁特性和微结构

"利用对靶磁控溅射法制备了一系列Ag/Fe/Ag纳米薄膜,沉积态样品Fe层厚度固定为35 nm,Ag层厚度为1、2、3、4、5 nm．随后对沉积态样品进行了退火处理,退火温度分别为200、300、400、500、600 ℃ , 退火30 min． 利用VSM测量了样品的磁特性, 利用SPM观察样品表面形貌和磁畴结构,并且利用XRD分析了样品的晶体结构．研究结果表明,沉积态样品随Ag层厚度的变化,垂直和平行膜面矫顽力均先增加后减小．当Ag层厚度为3 nm时,垂直膜面矫顽力最大约为260 Oe,样品颗粒分布均     

Microwave switching behaviors of Fe/Ag/Fe/Ag epitaxial films

In this study, Fe/Ag/Fe/Ag ferromagnetic structures were epitaxially grown on a GaAs(1 0 0) substrate. Using the Network Analyzer (Agilent 8510C), FMR (ferromagnetic resonant) signals were observed in samples as the in-plane magnetic field was applied to either hard- or easy-axes. Of interest was that our sample demonstrated a FMR-switching behavior in hard-axis but not in easy-axis. The detecting data showed that the switch magnetic field was much smaller than what has been stated previously in Fe/Cu/Fe systems by other laboratories. In addition to the frequency switch in FMR, we also observed a magnetic reversal behavior in its M–H curve. Data presented that both of the FMR and magnetic reverse took place in the same direction (hard-axis).     

Noncollinear magnetic hyperfine fields in the Ag spacers of Fe/Ag multilayers

Nearly perpendicular magnetic hyperfine fields have been observed for the first time in the Ag "spacers" of Fe/Ag multilayers using low temperature nuclear orientation of (110)Ag(m) at 6 mK. At the same time, vibrating sample magnetometry measurements at temperatures down to 4 K have shown the magnetic anisotropy of the Fe to be in plane. The direction of the Ag hyperfine field is thus noncollinear (nearly orthogonal) to the Fe anisotropy. These results are compared with full potential linearized augmented plane wave calculations using the wien97 code.     

Construction of Ag/AgCl nanostructures from Ag nanoparticles as high-performance visible-light photocatalysts

A combined strategy of in situ oxidation and assembly is developed to prepare Ag/AgCl nanospheres and nanocubes from Ag nanoparticles under room temperature. It is a new facile way to fabricate Ag/AgCl with small sizes and defined morphologies. Ag/AgCl nanospheres with an average size of 80 nm were achieved without any surfactants, while Ag/AgCl nanocubes with a mean edge length of 150 nm were obtained by introduction of N-dodecyl-N,N-dimethyl-2-ammonio-acetate. The possible formation mechanism involves the self-assembly of AgCl nanoparticles, Ostwald ripening and photoreduction of Ag⁺ into Ag⁰ by the room light. The as-prepared Ag/AgCl nanospheres and nanocubes exhibit excellent photocatalytic activity and stability toward degradation of organic pollutants under visible-light irradiation. It is demonstrated that Ag/AgCl nanocubes display enhanced photocatalytic activity in comparison with Ag/AgCl nanospheres due to the more efficient charge transfer. This work may pave an avenue to construct various functional materials via the assembly strategy using nanoparticles as versatile building blocks.

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Graphical abstract A combined strategy of in situ oxidation and assembly was developed to construct Ag/AgCl nanospheres and nanocubes from Ag nanoparticles, which exhibited highly photocatalytic activity and good stability for degrading methyl orange under visible light irradiation.

     

基于Ag/Ge/Ag阳极的as

通过在Ag层中引入一层Ge薄膜, 获得了具有低反射率和高反射相移的Ag/Ge/Ag复合阳极, 并制备了基于该阳极的蓝光顶发射有机电致发光器件.阳极高的反射相移使得器件在有机层厚度为100 nm时获得了顶发射蓝光发射, 且阳极较低的反射率减弱了器件内的微腔效应, 使得其电致发光光谱在不同视角下具有良好的稳定性.当Ge的厚度为20 nm时, 器件性能表现最为优良, 最高亮度和最大电流效率分别可达3 612 cd/m²和5.4 cd/A, 且色坐标在视角从0°变化到60°时仅移动了(0.007, 0.006).     

Charge‐transfer contributions in surface‐enhanced Raman scattering from Ag,Ag2S and Ag2Se substrates

The degree of charge‐transfer in Ag–4‐mercaptopyridine (Mpy) and Ag₂S–4‐Mpy systems is investigated by use of surface‐enhanced Raman spectroscopy (SERS). Ag₂S and Ag₂Se nanoparticles are prepared on the basis of the former formation of Ag nanoparticles to make the SERS analytical objects comparable. We utilize the intensity of the non‐totally symmetric modes (either b₁ or b₂) as compared with the totally symmetric a₁ modes to measure the degree of charge‐transfer. We find ~25% of charge‐transfer contribution for Ag–4‐Mpy, whereas 81 ~ 93% for Ag₂S–4‐Mpy. It means that the charge‐transfer resonance contribution dominates the overall enhancement in SERS of Ag₂S–4‐Mpy. Energy level diagram is applied to discuss the likely charge‐transfer transition between Ag, Ag₂S, Ag₂Se and 4‐Mpy. This article may point out the link among the three main resonance sources and could enable some insights into the electronic pathways available to the metal‐molecule and semiconductor‐molecule systems. Copyright © 2012 John Wiley & Sons, Ltd.