XPS Analysis of Ni and Oxygen in Single-Sintered SrTiO_3 Multifunction Ceramic

XPS analyses have been performed to investigate the chemical conditions of Ni and oxygen on grain surfaces in single-sintered SrTiO3 capacitor-varistor ceramic doped with Nb2O5 and NiO. It is ascertained that Ni is in form of Ni2+ ions, which substitute for Ti4+ ions on grain surfaces during the oxidizing annealing. Moreover, it is confirmed that three kinds of chemically adsorbed oxygen such as O2, O and O-2 are formed on grain surfaces. It is proposed that these behaviors contribute greatly to the generation of multiple types of grain boundary acceptor states in the ceramic.

Synthesis,properties and XPS analysis of Cu-,Ni-,Ti-based metallic glasses

Metallic glasses(MG)represent an interesting group of materials as they possess outstanding physical,chemical and mechanical properties compared to their crystalline counterparts.This paper reviews the synergistic influence of Ni and Nb elements on thermal stability of supercooled liquid and corrosion resistance of as-cast Cu-Zr(Hf)-Ti-Ni-Nb bulk metallic glasses(BMGs).Additionally,in-situ second phase reinforced Cu-based BMG composites with high corrosion resistance and excellent mechanical properties are investigated.On the other hand,this paper reports the development of ultra-high corrosion resistant Ni-based metallic glasses at high temperatures for their potential applications.Corrosion resistance and XPS analysis of the Nifree Ti-based BMG are also introduced.

XPS Analysis of α-B/C:H Film Deposited by ICRF Boronization

A new and safe boronization technique - ICRF boronization using carborane has been successfully developed on HT-7 superconducting tokamak. X-ray photoelectron spectroscopy (XPS) is used to analyze the properties of the fresh films and films exposed to plasma disCharges.Film deposited on stainless steel (SS) and molybdenum (Mo) show similar properties with a relatively high value of B/C, they are uniform through the layer and getter oxygen dramatically when being exposcd to plasma discharges. The films also show a reduced erosion rate.

XPS STUDY OF SUPERCONDUCTING Dy-Ba-Cu-Fe-O CERAMICS

The system DyBa2Cu3-xFexO7-delta(x=0.00, 0. 03, 0. 18) has been studied using X-ray photoelectron spectroscopy. XPS results show no evidence of valency state of Cu other than 2 in samples whether Fe-doped or not. Significant changes in the O-1s spectra were found with increasing Fe content. rt seems that by the substitution of Fe for Cu the oxidation state of Cu was little affected while it affected apparently the O-1s peaks. The results are discussed in detail.

Synthesis of Pb-Feldspar by Ion Exchange Reaction and Its Implications

Feldspar and Pb（NO3）2 were mixed and reacted at T=380℃ to synthesize Pb-feldspar. In the XRD （X-ray diffraction） pattern of the product, the d values （crystal lattice spacing） of the five peaks are 0.654, 0.342, 0.332, 0.327 and 0.257 nm. The XPS analysis results show that the binding energy of Pb 4f（7/2） in the feldspar was between 137.81-138.03 eV. Pb^2＋ can replace alkali and alkali earth cations in the feldspar structure through ion exchange reaction to form Pb-feldspar.

Modeling and experiments of N-doped vanadium oxide prepared by a reactive sputtering process

An original numerical model, based on the standard Berg model, is used to simulate the growth mechanism of Ndoped VOx deposited with changing oxygen flow in the reactive gas mixture. In order to compare with the numerical model, N-doped VOx films are prepared by reactive magnetron sputtering from a metallic vanadium target immersed in a reactive gas mixture of Ar＋O2＋N2. Both experimental and numerical results show that the addition of N2 to the process alleviates the hysteresis effect with respect to the oxygen supply. Film compositions obtained from the XPS analysis are compared to the numerical results and the agreement is satisfactory. The results also show that the compound of VN is only found at very low O concentration because of the replacement reaction of VN by O2 atoms with higher oxygen flow rate.

Effect of Counterface Materials on Friction and Wear Behavior of Double Glow Glasma Discharge Surface Alloying on Ti22Al25Nb Alloy

Samples of surface chromising layer were prepared by the double glow plasma discharge technique. X-ray diffraction and X-ray photoelectron spectroscopy（XPS） analysis of dif-ferent elements confirmed the formation of chrome in the layer. Their tribological properties were investigated by pin-on-disk tribometer. Silicon nitride, GCr15, and nickel-based alloy were selected as counterface materials. Results indicated that the lowest friction coefficients and wear rate were ob-tained when substrate and chromising layer against nickel-based alloy, and tribological properties of chromising layer were better than those of substrate. The highest friction and wear rate were samples against silicon nitride alloys. In the case of three rubbing pairs, the unchangeable materials against different hardness counterfaces leaded to different wear mechanisms. Samples against silicon nitride exhibited abrasive mechanism, and when GCr15 and nickel-based alloy were used as counterface, transfer film and glaze layer formed on the contact surface, which played the main role in decreasing friction and wear.

Synthesis and Characterization of KFeP_(2)O_(7) Nanoparticles Implanted in Silica

Rivers and aquifers are increasingly affected worldwide by the action of agro-industrial pollution. Facing this challenge, nanoparticles have found a wide range of applications in the decontamination and remediation of water, given the characteristics which make them highly reactive to specific substances. One of the simplest ways of gaining access to these particles is through their synthesis over a sufficiently rigid matrix of manageable size. This report describes the synthesis and characterization of nanoparticles of iron and potassium diphosphate (KFeP2O7) synthesized on silica gel beads (SiO2). Analysis by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) have been applied in order to determine the mineral phases and morphology of the synthesized compounds. Complementary tests were conducted so as to determine surface characteristics such as specific area by the BET method and point of zero charge (pHpzc) by mass titration. The acid-base titration enabled to determine the adsorptive nature of nanoparticles and their response to a pH range from 1 to 12.

Chemical Coupled PEDOT:PSS/Si Electrode: Suppressed Electrolyte Consumption Enables Long‑Term Stability

Huge volume changes of Si during lithiation/delithiation lead to regeneration of solid-electrolyte interphase(SEI)and consume electrolyte.In this article,γ-glycidoxypropyl trimethoxysilane(GOPS)was incorporated in Si/PEDOT:PSS electrodes to construct a flexible and conductive artificial SEI,effectively suppressing the consumption of electrolyte.The optimized electrode can maintain 1000 mAh g^−1 for nearly 800 cycles under limited electrolyte compared with 40 cycles of the electrodes without GOPS.Also,the optimized electrode exhibits excellent rate capability.The use of GOPS greatly improves the interface compatibility between Si and PEDOT:PSS.XPS Ar+etching depth analysis proved that the addition of GOPS is conducive to forming a more stable SEI.A full battery assembled with NCM 523 cathode delivers a high energy density of 520 Wh kg^−1,offering good stability.

Effects of Cr2O3 doping on the microstructure and electrical properties of （Ba,Ca）（Zr,Ti）O3 lead-free ceramics

Lead-free ceramics （Ba0.85Ca0.15）（Zr0.1Ti0.9）O3-x wt,%Cr2O3 （BCZT-xCr） were prepared via the conventional solid-state reaction method. The microstructure and electrical properties of BCZT-xCr samples were systematically studied. XRD and Raman results showed that all samples possessed a single phased perovskite structure and were close to the morphotropic phase boundary （MPB）. With the increase of the Cr content, the rhombohedral-tetragonal phase transition temperature （TR-T） increases slightly, and the Curie temperature （Tc） shifts towards the low temperature side. XPS analysis reveals that Cr3. and Cr5＊ ions co-existed in Cr-doped BCZT ceramics, indicating the different impact on the electrical properties from Cr ions as ＂acceptor＂ or ＂donor＂. For the x = 0.1 sample, relative high piezoelectric constants d33 （-316 pC/N） as well as high Qm （-554） and low tan6 （-0.8%） were obtained. In addition, the AC conductivity was also investigated. Hopping charge was considered as the main conduction mechanism at low temperature. As the temperature increases, small polarons and oxygen vacancies conduction played important roles.

Surface composition change of chlorine-doped catalyst Ni(Clx)/CeO2 in methanation reaction

The oxide sample NiO/CeO_2 with feed atomic ratio of Ni/Ce at 40%, prepared by co-precipitation method and calcination at 500 oC for 2 h, was impregnated by aqueous solution of NH_4Cl to dope chlorine ions. After the impregnated samples were dried and calcined at 400 oC for 2 h, the calcined samples NiO（Cl_x）/CeO_2（x=0.1–0.5） were characterized by means of X-ray diffraction（XRD） and temperature programmed reduction（TPR） techniques. It was comfirmed that the doped chlorine ions hindered reduction of Ni^（2＋） ions in the calcined samples, and suppressed adsorption of CO_2 and CO on the reduced sample Ni（Cl_（0.3））/CeO_2. The reduced samples Ni（Cl_x）/CeO_2（x=0.0–0.5） were used as catalysts for selective methanation of CO in H_2-rich gas. When chlorine ions were doped at the feed atomic ratio of Cl/Ce（x） equal to 0.3–0.5, CO in the H_2-rich gas could be removed to below 10 ppm with a high selectivity more than 50% in a wide reaction temperature range of 220–280 oC. However, the selectivity of CO methanation decreased with reaction time in the durability tests over the catalyst Ni（Cl_（0.3））/CeO_2 at the reaction temperature of 260 oC and even at 220 oC. The lowering of the selectivity was found to be related with the surface composition change of the catalyst in the catalytic reaction.