| dc.description.abstract | We make Silver nanoparticle by evaporation,and mix with PbO nanoparticle by different mass ratio.The mass ratio we choise is(Ag)x(PbO)100-x(X=70、50、30).Because PbO nanoparticle is insulator,so that we can make different distance between Silver nanoparticle by mixing PbO nanoparticle.On the other hand, density in sample is a important factor,we can control the factor by variety’s pressure.Then we discuss the electron transport behavior, we try to explain the phenomenon by VRH model.The result is the model cant suit experiment data.In biggest density’s sample,the resistivity increase between 25~300K,we think the phenomenon come from properties of Silver bulk.
Furthermore,we make three sample without pressure,the mass ratio of these sample are (Ag)30(PbO)70、(Ag)20(PbO)80、(Ag)10(PbO)90.The electron transport behavior is caused by tunneling,we think the gap between Silver nanoparticle is enough to tunnel by electron.Accorging to fitting parameters,we found the tunneling energy come from applied electric field. In magnetoresistivity experiment,we observe the change of positive to negative magnetoresistivity. We think the electron tunneling effect make this phenomenon.
In experiment of magnetization,we observe the paramagnetism in small field,and appearance of diamagnetism when applied magnetic field over 2 tesla.According to the definition of tunneling magnetoresistivity,the magnetization can explain magnetoresistivity. | en_US |