Transport Properties Of Graphene And Organicmetal-molecular Clusters Spintronics Devices

Spintronics has attracsted much interest for decades as it holds promise for the next generation of spin electronic devices with improved performance and enhanced functionality. Graphene and one-dimensional (ID) organic spintronics as an important branch of spintronics, has been the subjuect of continuous theoretical and experimental research3. Because of their finite size, these systems display novel propertise that make them promising candidates for application in high-density information storage and quantum computing. Motivated by theoretical predictions, much interest has been focused on the area of graphene nanoribbons and one-dimensional (1D) magnetic nanomaterials, for example it is getting a different energy band structure of graphene by cropping and sandwich organic molecular wire synthesized using intricately tailored organometallic materials. Several experimental groups have successfully produced iso-lated and stable2D crystals of graphene at room temperature. Graphene nanoribbons have attracted enormous attention due to its potential application in nanoelectronics.And the advantages of one-dimensional sandwich organic molecular wire are the smallest, cheap, low-weight, mechanically flexible and chemically interactive. One-dimensional organometallic sandwich molecular wires have been reported to have many properties, such as half-metallic, high-spin filter and negative differential resistance. And they can be chemical synthertized easily by cutting.My investigations focus on the aspects as follow:First, I have used adsored-grahene nanoribbons to design and construct molecular junctions to investigate the magnetic properties and transport properties by using first-principles calculations of Nonequilibrium Green’s Function combining density functional theory approach. The investigations emphasize the mechanism of negative magnetic resistance and and nonlinear current voltage curve, which propose the theoretical elements for fabrications of molecular electronics devices. Second, I study some one-dimensional organicmetal magnetic materials for providing the theoretical and experimental elements for fabrications of one-dimensional spintronics device. Low-dimensional spintronics is the interdiscipline which combines the advantages of electronics and spintronics. My calculations find that organometallic multidecker sandwich complexes coupled with gold electrode generate spin-polarized currents and can serve as highly effective spin-filters, besides they also exhibite adistinctive feature of negative differential resistance (NDR). To my surprise, we also have found some new organicmetal half-metallic material with one-dimensional sandwich molecule structure.