Preparation And Electrical Conductivity Of Binary Metallic(Ni-Ag、Cu-Ag)nanoparticles

With the continuous development of electronic industry,electronic materials play an increasingly important role in industrial production.Among them,metal conductive nanomaterials have a very important position in the industrial field because of its unique performance.More and more nanomaterials are going to be made with more excellent conductivity and within lower price.For the time being,the most widely used nano-conductive materials in industrial production are Ag-based nano-conductive materials.Ag,as the metal with the most excellent conductive properties,has a great value of application.However,Ag-based nanomaterials have the disadvantage of high cost.In order to achieve lower prices,Ni-based and Cu-based nanoparticles come to be the primary alternative products.At present,chemical method is the main method to prepare metal-based nanoparticles.It has many shortcomings such as complex reaction process,low production rate,impure products,contamination of reactants and so on.On the contrary,DC arc plasma,as an effective method for preparing nanomaterials,has the advantages of pure products and large-scale production.Preparing for Ni-based and Cu-based nanoparticles by DC arc plasma and apply them for electronics industry have great engineering significance.In this paper,Ni-based and Cu-based nanoparticles with various compositions were prepared by DC arc plasma method.The conductive samples were prepared by using them as raw materials,and their conductive properties in practical application were explored.The specific experimental contents are as follows:1.Pure Ni and Cu nanoparticles were prepared by DC arc plasma.The basic physical properties of pure nanoparticles were characterized by XRD and TEM.Then we press two kinds of nanoparticles into conductive sheet and test their conductivity.Then we take the prepared nanoparticles as the conductive agent for making the conductive samples according to the established process found by other people of our laboratory.And the electrical properties of the conductive samples were tested under different experimental conditions.Results show that the prepared nanoparticles of Ni and Cu are pure and uniform in morphology.But the intrinsic conductivity of the nanoparticles and the conductivity of sintered samples prepared by Ni/Cu particles still have room for improvement.2.According to the above results,the electrical properties of Ni-based nanoparticles were improved by adding appropriate Ag elements.Ni-Ag bimetallic nanomaterials were prepared by DC arc plasma using Ni and Ag micron powders with mass ratios of 5:1,10:1 and 15:1,respectively.The electrical properties of Ni-Ag nanoparticles and pure Ni nanoparticles with the same preparation process were compared.The experimental results show that the composition of Ni-Ag composite nanoparticles prepared by DC arc method is different from that of the raw materials due to the different evaporation rates of Ni and Ag;the prepared bimetallic nanoparticles are pure and there are no complex Ni and Ag compounds;The conductivity of Ni-based nanoparticles doped by Ag element is obviously improved: The resistivity of thin films pressed under 25 MPa can be improved.The resistivity of the sintered body prepared by high temperature sintering method at 450 °C is 1.83 x 10-3Ω?cm.The SEM results show that the increase of sintering temperature is beneficial to the formation of conductive network in the conductive sample and the improvement of the conductive property of the sample.3.Cu-Ag composite nanoparticles were made according to the preparation process of Ni-Ag composite nanoparticles.The physical properties of samples prepared under different conditions were tested.Results show that the solid solution of Cu and Ag elements in Cu-Ag composite nanoparticles prepared by DC arc method is beneficial for mixing of the two elements more uniformly;the conductivity of Cu-based nanoparticles doped by Ag element is also improved significantly.That is because of the reduction of surface oxidation of Cu element which will decrease of electrical properties significantly;it is proved that DC arc plasma method is an effective method for preparing Cu-Ag composite nanoparticles.The physical method of bimetallic nano-powders has certain engineering application significance.