Si_p/1199, Si_p/4032 and Si_p/4019 environment-friendly composites for electronic packaging applications with high volume fraction of Si particles were fabricated by squeeze-casting technology. Effects of microstructure, particle volume fraction, particle size, matrix alloy and heat treatment on the electrical properties of composites were discussed, and the electrical conductivity was calculated by theoretical models. It is shown that the Si/Al interfaces are clean and do not have interface reaction products. For the same matrix alloy, the electrical conductivity of composites decreases with increasing the reinforcement volume fraction. As for the same particle content, the electrical conductivity of composites decreases with increasing the alloying element content of matrix. Particle size has little effects on the electrical conductivity. Electrical conductivity of composites increases slightly after annealing treatment. The electrical conductivity of composites calculated by P.G model is consistent with the experimental results.

In order to improve the thermal properties of MMCs for electronic packaging, the concept of fabrication MMCs with particular interpenetrating phases(IPCs) was proposed. Based on the diffusion theory of reinforcement element in matrix alloys of some particular PMMCs, a novel fabrication method to produce IPCs was proposed. The Si/Al composites (65%Si, volume fraction) with interpenetrating phases were fabricated successfully by squeeze casting and hot press sintering technology. Microstructure observations indicate that the reinforcements Si are of three-dimensional continuous network and the composites are compact without obvious defects. The average linear thermal expansion coefficient (CTE) between 20 ℃ and 100 ℃ of the Si/Al IPCs is 8.27×10⁻⁶/K, and the thermal conductivity(TC) is 124.03 W/(m∙K), and the composites can meet the demands of electronic packaging. ROM model and Turner model can be used to predict the CTEs of IPCs, and the experimental , CTEs are between their theoretical and calculated values.

Trace amounts of La were utilized to improve the melting behaviors, microstructures, tensile properties and microhardness of Sn-3.0Ag-0.5Cu lead-free solder alloy. La has little effect on the melting behavior of Sn-3.0Ag-0.5Cu alloy according to the differential thermal analysis (DTA) tests. The X-ray diffraction (XRD) patterns show that β-Sn, Ag₃Sn and Cu₆Sn₅ coexist in the as-cast solder alloys and LaSn₃ phases emerge when adding 0.4% La. The microstructures modified by La are more uniform and much finer than that of baseline alloy, and the coarse LaSn₃ particles with complex dendrites are observed by optical microscopy (OM) and scanning electron microscopy (SEM) when the addition of La is up to 0.4%. The composition of the LaSn₃ phases is identified by energy-dispersive spectroscopy (EDS). There are considerable improvements in mechanical properties with 0.05% and 0.1% addition, but degenerations by adding 0.4%La. The Vickers microhardness of β-Sn and eutectic area are both enhanced with the addition of La and the microhardness of LaSn₃ is much larger than those of β-Sn and eutectic area.

The possibility of substituting 72.5Cu-22.7Zn-3.4Al brass for phosphorus bronze in some case that is now extensively used for elastic component, and purifying the scrap copper for recycling metal was investigated. By adding a little amount of rare earth Y into scrap copper and 72.5Cu-22.7Zn-3.4Al brass to research their structure and characteristics, especially the electric conductivity for scrap copper and HV for the brass were researched. The results show that the tensile strength, elongation and electric conductivity (IACS) of 0.38 mm strip of scrap copper with 0.04% Y, are 213.8 MPa, 23% and 98.5% that suit for the elastic components. The tensile strength, elongation and HV of 0.25mm strip of the brass with 0.03% Y are 665.1MPa, 2.86% and 226 that satisfy the usage requirement for the elastic components. Meanwhile, the cost is cheaper than phosphorous bronze because of implying 22.7% zinc in the brass, which has the actual application value.

A new environmental friendly cutting brass containing stibium instead of lead was produced by casting and rolling. The microstructure was observed and the mechanical, dezincification and cutting properties were studied. The results show that the white particles distribute in both grains and grain boundaries, and the particles are mainly intermetallics containing stibium. The tensile strength, yield strength and elongation percentage of half-hard Sb-brass is 461.72 MPa, 213.3 MPa and 15.67%, respectively. Corresponding to HPb59-1 by the size as well as appearance of the chips and the mechanism of free-cutting, the cutting property of unleaded free-cutting Sb-brass is excellent. The unleaded Sb-brass has excellent dezincification corrosion resistance, and the average depth of longitudinal section is about 295.4 μm, while the average depth of lateral section is about 214.7 μm, and it is feasible to develop a new unleaded free-cutting Sb-brass

Cu-coated graphite composites were prepared by an electroless plating method, and the composites were examined by scanning electron microscopy (SEM). The copper content of the composites was measured to reach 73% (mass fraction). Brush samples made with composites contents of 10%, 15% and 20% and with copper powders content of 11% were obtained. The results show that the resistivity of the brush samples decreases and hardness becomes higher with increasing composites content. Copper is dispersively distributed in the brush samples made with the composites, whereas copper agglomerates in Cu-graphite mechanical mixture. For the same Cu content, Cu-coated graphite composites possess lower resistivity and higher hardness than Cu-graphite mechanical mixture. A new type of electric brush was obtained by using Cu-coated graphite composites, the wear and durability tests carried out on a HGH5435M120 AC motor indicate that its service life reaches 250 h. The electric brushes possess relatively low resistivity (275 mW∙m) and good wear resistance, so they are very suitable for high-speed micromotors.

Multi-walled carbon nanotube (MWCNT)-reinforced copper composite was fabricated by a novel method, which involves solution phase synthesis of MWCNT-implanted cuprous oxide composite spheres, formation of MWCNT/ copper composite spheres after reduction in H₂ atmosphere and preparation of the MWCNT/copper bulk with vacuum hot pressing. The SEM images of the fracture surfaces indicate that MWCNTs are homogeneously dispersed in the composite and bonded to the matrix. In addition, the thermal expansion of the composites with various MWCNT contents (0%, 1% and 5%, mass fraction) were investigated. The coefficient of thermal expansion (CTE) decreases with increasing MWCNT content, which are all much lower than that of pure copper.

The compositions, structures and properties of four kinds of Cu-Al alloys with different constituents were researched by means of optical microscopy, scanning electron microscopy, X-ray diffractometry and damping detection. The structures and properties of Cu-11Al-5Mn-RE experienced different heat-treatment processes were also studied. The results indicate that the damping capacity and microstructure of the alloys are improved by adding Mn and RE elements. Cu-11Al-5Mn-RE obtains the best comprehensive physical performance because of the cooperation of Mn and RE elements. Aging at 200 ℃, the damping capacity gets to the maximum. At 400 ℃, its mechanical property decreases while its damping capacity still remains, indicating its resistance to martensite decomposition and aging at moderate temperature.

The microstructures and properties of Cu-8.0Ni-1.8Si alloy subjected to different heat treatments were examined by mechanical and electrical properties measurements, optical and transmission electron microscopes observation. The results show that the precipitation process during aging can be accelerated by the cold deforming before aging. As the Cu-8.0Ni-1.8Si alloy is subjected to solution treatment at 970 ℃ for 4 h, cold rolling to 60% reduction, and then aging at 450 ℃ for 60 min, its properties are σ_b=1 050 MPa, σ_0.2=786 MPa, δ=3.2% and conductivity 27.9%(IACS). The strengthening mechanisms of the alloy include spinodal decomposition strengthening, ordering strengthening and precipitation strengthening. The precipitation of the alloy is nano-scale Ni₂Si phase.

To optimize processes for stable commercial production of C194 alloy sheet and strip, several key steps were investigated. Various procedure and the parameters for melt purifying, finishing rolling temperature, split aging parameters, and water cooling capacity during casting and hot rolling were analyzed. The results imply that shield gas atmosphere along with alloying element of Mg and Ce help greatly on purifying the melt. C194 alloy sheet and strip with finishing rolling temperature higher than 750 ℃ and split aging treatment at 550 ℃, 2 h+450 ℃, 2 h can obtain excellent integrity properties. The cooling capacity during casting and on-line quenching after hot rolling are also key factors influencing the quality of C194 alloy sheet and strip.

To promote the solution of chromium in copper and the purity of copper-chromium (Cu-Cr) alloy, vacuum continuous casting (VCC) process was employed to fabricate the Cu-Cr alloy required for electrode material. Cu-0.6Cr (containing 0.6%(mass fraction) chromium) alloy bar with a diameter of 12 mm was cast with a constant rate of 250 mm/min. The microstructure, mechanical properties, and physical properties were discussed. After solid solution strengthening and aging treatments, Cu-0.6Cr alloy fabricated by VCC process has higher tensile strength (σ≥314 MPa), elongation rate (δ≥34%), conductivity (≥80.5% IACS), and hardness (80 HRB) compared to the as-cast alloy.

Acoustic-frequency induction melting together with rapid quenching was used to prepare Mg₆₅Cu₂₅Y₁₀ bulk amorphous alloy containing primary crystalline phases. Transmission electron microscopy (TEM), X-ray diffractometry (XRD), environmental scanning electron microscopy (ESEM) and atomic force microscopy (AFM) were used to study the amorphization and morphology of the prepared alloy. Under micro condition, the sample alloy is composed of amorphous structure with cauliflorate shape, primary CuMg₂ dendrite phase, mixed primary CuMg₂ and Cu₂Y crystalline phases, as well as Mg phase with small size. Further study under sub-micro condition shows that, the planar amorphous structure of cauliflorate shape is composed of the three-dimensional sub-micro morphology of “bulge-concavity” pattern, which extends into the space in terms of certain period. It is estimated that the major factors influencing the micro and sub-micro morphologies of amorphous alloy are its super-cooling liquid structure, rapid quenching transformation, as well as the melting conditions.

After substituting partial Cu and Mg with Zn or Al elements for Mg₆₅Cu₂₅Y₁₀ alloy, respectively, the metallic glass plate samples with thickness of 2−3 mm were prepared by water-quenching, their respective glass-forming ability and thermal stability were studied by using differential thermal analysis (DTA) and X-ray diffraction (XRD). Using Kissinger equation, the activation energies of crystallization of these metallic glasses heated with a constant rate were calculated. The results show that Al element is greatly harmful to the glass-forming ability of Mg-Cu-Y alloys and cannot acquire bulk amorphous alloys; nevertheless, the effect of Zn element addition is indeterminate for various components. The magnitudes of thermal stability are also revealed.

In order to study high-frequency soft magnetic properties of Finemet amorphous alloy, the microstructural change and nanocrystallization under different heat treatment conditions were investigated by XRD and TEM. The crystallite size of α-Fe was calculated from the XRD pattern using the Scherrer formula, while the high frequency magnetic properties were measured at room temperature by TPS-200SA exchange tester. The results of XRD and TEM indicate that the nanocrystallization occurs at 500 ℃. When the annealing temperature increases to 560 ℃, the amorphous alloy becomes totally nanocrystallized and the crystallites distribute homogeneously, thus an excellent combination of soft magnetic properties is obtained.

Heat treatment of carbon nanotubes (CNTs) was carried out under ammonia atmosphere and then CNTs were modified by Triton x-100 (CNTs-T). Ni-B amorphous alloy catalysts supported on CNTs and CNTs-T were prepared by impregnation-chemical reduction method. The catalysts were characterized by TEM, ICP, XRD, BET and CO chemisorption, and studied in the acetylene selective hydrogenation. The results show that homogeneous Ni-B amorphous particles with mean size about 10 nm are successfully prepared on CNTs-T. Compared with Ni-B/CNTs, nickel loading of Ni-B/CNTs-T is increased by about 14.6%. Furthermore, the activity and selectivity of Ni-B/CNTs-T are much higher than those of Ni-B/CNTs in the acetylene selective hydrogenation under comparative condition.

Iron polymeric hydroxygroups pillared clays (Fe-PILC) were prepared by Na⁺-montmorillonite with iron pillaring agent. 2.01Au/Fe-PILC catalyst was obtained by deposited-precipitation (DP) method. 2.52Au/Fe-oxide catalyst was prepared by co-precipitation method. The catalytic activity of these catalysts was measured by catalytic combustion of formaldehyde. The catalyst of 2.01Au/Fe-PILC exhibits the high catalytic activity. The catalytic combustion reaction of formaldehyde proceeds at considerable rates at 20 ℃ and complete burn-off of formaldehyde is achieved at 120 ℃. The structure of catalysts, the valence state of gold and the size of gold particles were investigated by means of X-ray powder diffractometry, X-ray photoelectron spectroscopy and transmission electron microscopy. The results show that gold atoms with partially positive charge exist in the catalyst and play an important role in the catalytic activity. In addition, nano-sized, well-dispersed gold particles and good adsorption properties of support are necessary to obtain high activity Au catalysts for catalytic combustion of formaldehyde.

Eu²⁺/Gd³⁺-codoped nanocrystalline titania catalysts were prepared by a modified sol-gel method. Powder X-ray diffraction, Transmission electron microscopy and UV-Vis spectra analyse were carried out to characterize the catalysts with different Eu²⁺/Gd³⁺contents.The photocatalytic efficiency was evaluated by the photodegradation of methyl orange in an aqueous solution under natural light irradiation. It has been confirmed that Eu²⁺/Gd³⁺-codoped titania could be excited by natural light. The higher natural light activity is due to the codoping of Eu²⁺/Gd³⁺. An optimum synergetic effect was found for a mass ratio of Eu/TiO₂ equal to 1.0% and Gd/TiO₂ equal to 0.5%. The effects induced by Eu²⁺/Gd³⁺-codoped on the titania catalysts may be explained in terms of Gd³⁺→Eu²⁺ energy transfer to affect the photocatalysis activity of the titania catalysts.

A new type of photocatalysts MWCNTs/TiO₂-NTs nanocomposites prepared by combining multi-walled carbon nanotube (MWCNTs) with TiO₂-derived nanotubes were synthesized by a modified hydrothermal method. The SEM, XRD, UV-Vis and TG-DTG were used to characterize its property. The produced MWCNTs/TiO₂-NTs nanocomposites were used as the catalysts for photo-degradation of aquatic humic substances, Their photocatalytic efficiency was evaluated by the photodegradation of humic acid in an aqueous solution under ultraviolet light irradiation. The results show MWCNTs could enhance the activity of the photocatalysts; the best degradation efficiency was obtained by using MWCNTs/TiO₂-NTs nanocomposites containing 20% MWCNTs as the photo-catalyst.

A composite catalyst Nafion-Pt-H_xMoO₃ was prepared on a glassy carbon by cyclic voltammetry methods in sulfuric acid solution containing Na₂MoO₄, H₂PtCl₆ and Nafion, and its activity for the methanol oxidation was studied with Pt-H_xMoO₃ as comparison. It is found that the electrocatalytic activity and the stability of Pt-H_xMoO₃ are improved by the Nafion. The activity of Pt-H_xMoO₃ reaches its maximum when the content of Nafion in the preparation solution is 0.012%(mass fraction). In this case the oxidation peak current of methanol on Nafion-Pt-H_xMoO₃ is 1.76 times larger than that on Pt-H_xMoO₃ and keeps unchanged when the potential is set at 0.3 V (vs Hg-Hg₂SO₄) for 5 000 s in 1 mol/LCH₃OH+0.5 mol/L H₂SO₄ solution. The results from energy dispersive spectroscopy show that the content of Nafion in the composite is 0.57%. The results from scanning electron spectroscopy show that the composite of Nafion-Pt-H_xMoO has a gain size of about 90 nm and distributes more uniformly than Pt-H_xMoO₃.

The powders of amorphous nanocrystalline Fe₈₅Si₂Al₆Cr₇  were prepared by high energy ball milling for different times, and measured by XRD and network analyzer. The results show that: 1) nanocrystalline microstructure remarkably improves the microwave permeability, and the permittivity is controlled effectively; 2) by adding proper dyeing auxiliary (such as copper phthalocyanine), the magnetic properties of powders are improved when the particle sizes milled are excessively small.

Effects of Zr content on the structural, morphological, and magnetic properties of rapidly quenched Sm(CoFe_0.11Cu_0.10Zr_x)₇ (x=0−0.04) alloys were investigated. The Zr-free ribbon crystallizes with the 1׃7H structure as a major phase while the ribbons with Zr addition adopts the 2׃17R structure type. The ribbons with x=0.03 exhibits a highest coercivity, H_ci=933.7 kA/m, because a smaller uniform cellular structure along with a lamellar phase is formed. The decrease of H_ci above x＞0.03 is mainly related to the formation of 2׃7 phase.

By designing the shape of the original surface curve (sine-wave and square-wave), macroscopic domains with different dislocation density were introduced into the TiNi alloys and materials were endued with the characteristics of composites. Dilatometer (DL) and the differential scanning calorimeter (DSC) were used to study the properties of in-situ composites of TiNi alloys. The results show that the reverse transformation temperature range of in-situ TiNi composites with sine-wave surface is significantly enlarged. However, two endothermic peaks appear on DSC curves in the first heating process for these samples with square-wave surface. It is presumed that the interactions between the dislocation texture and martensite variants introduced when the TiNi martensite is cold rolled at room temperature might be responsible to the phenomena, which are compared with cold-rolled sheets with flat surface. All the phenomena above show it is feasible to control the thermal properties of a material by a proper design of the dislocation texture.

Ni/Al₂O₃ composites were prepared by hot pressing approach. The relationship between their microstructure, mechanical, dielectric and magnetic properties with Ni particle content was studied. By increasing the amount of, metal in the composite, the relative density and the bending strength decrease gradually. The possible reason is that non-wetting between Ni and alumina in the preparation results in weak adhesion of the Ni/Al interface. For the composites, the maximum fracture toughness is 6.4 MPa∙ m^1/2, which is about 25% higher than that of pure alumina ceramic. The increase in toughness of the Ni/Al₂O₃ composites is due to the deformation of nickel particles. The complex dielectric constant measurements indicate that the real part and the imaginary part increase greatly with the Ni content in the frequency range of 8.2−12.4 GHz. The real part and the imaginary part of complex permeability of the composites also increase with increasing Ni content.

Ni/C core-shell composite powders were prepared by electroless nickel-plating. The effects of concentration of NiSO₄, bathing temperature, ratio of hydrazine hydrate to NiSO₄, pH of the solution, amounts of complexing reagent and surfactant, bath load of activated carbon and reaction time, and so on, on the preparation of Ni/C core-shell composite powders were studied. The results show that the principal factors for Ni/C composite powders preparation are bathing temperature, ratio of hydrazine hydrate to NiSO₄ and pH of the solution. The optimum conditions are plating at 90 ℃ with pH10.7 and molar ratio of N₂H₄×H₂O to Ni²⁺of 3.0. The plated nickel powders are observed to be sphere-like in morphology with size about 100 nm. The maximum dielectric loss of Ni/C core-shell composite powders is about 0.35, and its magnetic loss was low with value about 0 in 2−16 GHz.

Nano-hydroxyapatite (nHA) and titanium (Ti) powders with different ratios were prepared by mechanical ball milling, and then sintered in vacuum environment. The microstructure and phase composition of Ti-based biocomposites with different contents of nHA(5% and 10%, in volume fraction) were investigated. Meanwhile, the phase composition of pure Ti was studied for contrast. The results show that Ti phase forms a finer continuous network microstructure with few porous after milling and sintering. The higher amount of nHA powders are added, the higher amount of porous are achieved, while the fracture morphology becomes coarser. The specimen with contents of 10% nHA has serious interface reaction after sintering at 1 100 ℃, it varies with the pure Ti specimen. Combined with the XRD and EDS analysis, it can be founded that elements Ca, P, O and Ti diffuse on the interface, and the phases of Ti, Ti₂O, Ti₅P₃, CaTiO₃ and TiO_x can be ascertained in nHA/Ti composites.

The high-purity AlON ceramics, AlON/Al₂O₃ and AlON/AlN multiphase ceramics were prepared by pressureless sintering under nitrogen-based atmosphere with raw materials of Al₂O₃, AlN and Al powders. The compositions of the phase were determined by XRD, the fracture appearance was analyzed by SEM. The results indicate: the aluminum oxynitride phase in the AlON ceramics and other multiphase ceramics exist in the form of Al₅O₆N, whose solid-solution zone is 33.4%(mole fraction) AlN belonging to spinel structures. The average grain size of high-purity AlON is about 3 µm. The grain boundary is smooth without other phases. The density is 2.82 g/cm³, the microhardness (10 N) and about bending strength are 1 470 MPa and 94 MPa, respectively.

Hot pressed sintering were employed to prepare the sodium super ionic conductor (NASICON: Na₃Zr₂Si₂PO₁₂) ceramics using the powder with the corresponding composition from sol-gel method. The density, phase and microstructure of different samples sintered at different temperatures were analyzed and the dependences of density, phase formation, and the microstructure on the sintering temperature were investigated in detail. The AC electrical conductivity and the buck conductivity of the ceramics sintered at different temperatures were measured and discussed. Results show that the samples contain mainly monoclinic NASICON and no ZrO₂ phase was found no matter the sintering temperature is high or not. The sintering temperature mainly dominated the density, the microstructure and the electrical characteristics of the ceramics. The densities of the samples increase obviously as the sintering temperature increases and reach 99.4% when the sintering temperature is 1 150 ℃. With the increase of sintering temperature, both the density and crystal size of the samples increase obviously, resulting in the visible increase of ionic conductivity of the samples as the sintering temperature. When sintering temperature reaches 1 150 ℃, the ionic conductivity of the sample has the highest value of 3.6×10⁻³ S/cm, which could be attribute to the highest density and least crystal boundary due to largest crystal size of the ceramics.

To reduce the mass of the mirror, silicon carbide was used as the material and four light-mass structures were designed. The properties of SiC mirror open back structure with triangular cell, open back structure with hexagonal cell, sandwich structure with triangular cell, sandwich structure with hexagonal cell, were analyzed by using finite element method. The results of the static, dynamic, and thermal properties of the four kinds of SiC mirror indicate that the surface figures of the SiC mirrors are all satisfactory with the design requirements. The properties of the mirrors with sandwich structure are better than those with open back structure, except the high cost. And the mirror with triangular cell has better combination properties than the mirror with hexagonal cell. Considering the overall performance and the cost, open back structure with triangular cell is the most suitable for the SiC mirror.

Cracks and ruptures always occur during wire drawing process of 42% nickel-iron expansive alloy. In order to study the reasons of these phenomena, a method of metallographic observation in combination with sample electrolysis was used to characterize the non-metallic inclusions in the alloy wire. The results indicate that the inclusions in the alloy are oxidation products during the process of melting. There are single or complex phase inclusions composed of elements such as Al, Si, Ca, Ti, Fe, and O₂. Among them, the macro-inclusions are TiO₂ compound inclusions formed by the adhesion of Al and Si oxides on them. These inclusions are fragile ones with a low strain rate, as well as a rather high hardness, so that they are the main reason that leads to the surface cracks and ruptures in the alloy wires. The analysis has educed that the key point to enhance the product quality is to promote the cleanliness of the melt, control the types and quantity of non-metal inclusions in the alloy.

Gibbsite crystals display large varieties of shapes and sizes when grown from sodium aluminate solution. The usage of gibbsite is partly determined by morphology, therefore, controlling the gibbsite morphology in accordance with usage arrests interests of both merchants and scientists. In present study, the effects of organic additives with various functional groups, oleic acid, 1-octadecanol and stearic acid on gibbsite morphology were investigated at the concentration of 0.1 g/L. Experiments were performed at the temperature of 65 ℃. Samples of gibbsite crystals were obtained from the decomposition of the unseeded synthetic sodium aluminate solution. The morphologies of these gibbsite crystals were examined with SEM, which shows that functional groups influence gibbsite morphology intensively. The morphologies of gibbsite nucleated from the pure solution and solution containing oleic acid, 1-octadecanol and stearic acid are as follows: mosaic gibbsite consisting of various shapes of crystals, radial agglomerate consisting of hexagonal pallets, mosaic and ball like agglomerate consisting of block crystals and loose, radial crystal consisting of irregular tiny nuclei. The facts indicate that it is possible to control gibbsite morphology at the presence of additives with various functional groups. The action mechanism of functional group to morphology was also proposed.

The effect of dipole layer of Alq3 and metal on organic electroluminescence in organic light-emitting diodes (OLEDs) was discussed. The relations among energy level alignment, interface charge transfer and dipole layer formation were well analyzed. An interface dipole layer and charge transfer were observed by XPS and UPS. As for Alq3 with metallic film such as Al and Mg, N 1s, O 1s and C 1s all move to low binding energy. Both Alq3/Al and Alq3/Mg have different electron spectrum from that of simple Alq3 film. It is really the reason of the interface energy change that the metal atoms located near the interface move to organic layer and then chemically interact with O and C of Alq3. The injection voltage barrier heights of electrons at Alq3/Al and Alq3/Mg interface are 0.1 eV and 0.2 eV, respectively. Charge transfer lowers electrons injection voltage barrier height and forms good electrons injection interfaces. The width of dipole layer is about 5 nm. The knowledge of such interface dipole layer is essential for a proper understanding of the physical processes at the metal/organic interface.

A novel chemical process for producing well-defined copper particles with satisfied anti-oxidation property was described. The resultant particles were characterized by X-ray diffractometry and scanning electron microscopy. The results show that well-dispersed nano-copper particles with 70 nm in diameter are obtained from the water/organic solution containing 0.2 mol/L Cu²⁺ ion, with ammonia as ligand and ascorbic acid as reductant. In this process, the formation of copper-ligands in aqueous solution causes initial copper ions concentration very low, which is not only good to obtain homogeneous initial reaction solution, but also slower the initially drastic nucleation reaction rate. This makes the process more convenient for delaying the nuclei processes and for controlling the ultimate copper particles size. In addition, oleic acid acts as both a phase-transfer agent and a particle protector coordinating their carboxyl end groups on the new generated copper particles surface, the carbon tails of the oleic acids are pointed outwards from the surface of the synthesized particles. This organic film also seems to play an important role to prevent the new generated copper particles from oxidation.