Investigation On Magneto-Electron Properties Of One-Dimensional Carbon-Based Materials

The extensive concern and interest have been devoted to investigate various types of two-dimensional(2D)material since the graphene was fabricated successfully in 2004.The graphene nanoribbons or nanoflakes which derive from graphene will gain wide applications in future graphene-based electrical devices due to the unique physics and material characteristics.Here,by using the first-principles calculations based on the density functional theory,the magneto-electric properties of one dimensional carbon-based materials are studied.The research results may provide a reference for the electronic applications of nanomaterials.In this paper,we first introduced the discovery of 2D nanomaterials,such as graphene's research background,the present situation,the main research methods and the basic theory.On this basis,we focus the research on the magnetoelectric properties of penta-graphene nanoribbons(P-GNRs).Four different types of P-GNRs have designed and it is found that they are very versatile,presenting a rich and unique electronic nature.In the nonmagnetic state,owing to their particular band structures,P-GNRs show much promise for developing high-performance negative-differential-resistance devices and nano-transistors.Whereas in their six different magnetic configurations,they can yield semiconductor,magnetic semiconductor,or bipolar magnetic semiconductor(BMS)behaviors,the latter in particular may be of great use for developing next-generation information storage devices.More interestingly,an applied transverse electric field can transform a P-GNR from a magnetic semiconductor to a half-metal with a wide band gap of 0.88eV,which can achieve complete spin filtering at room temperature.Important advantages over graphene nanoribbons are thus expected.Then,we studied the magnetoelectric properties of phagraphene nanobribbons(PHAGNRs).there are three different edge structures,A-,B-and C-type,can be achieved by cutting phagraphene along a certain direction.It is found that for the nanoribbon with two A-type edge structures,it is nonmagnetic semiconductors.While for nanoribbons with B-type and/or C-type edge structure for two edges,they are magnetic metals in the ferromagnetic state but are spin-degenerate/spin-splitting semiconductors in the antiferromagnetic ground states.Particularly,for nanoribbons with A-type edge structure for one edge while with B-type or C-type edge structure for other edge,they have only the ferromagnetic ground state and present the BMS nature.The half-metallicity for a phagraphene nanoribbon can be realized by the application of a transverse electric field also.Besides,nanoribbons can maintain high carrier mobility even if they are tailored to as ribbons structure,indicating that they have a great potential in the application of electronic devices.Finally,the edge-functionlization effect of zigzag edged PHAGNRs(ZPHAGNRs)have been investigated systematically.And it is found that the half-metallicity in PHAGNRs can be achieved by asymmetric edge modification and the half-metal bandgap decreases with the concentration of the edge substituents increasing.In addition,the transverse electric filed can manipulate the the electronic properties of nanoribbons efficiently.More importantly,nanoribbons can achieve the magnetic phase transition,namely,transforming among paramagnetism,antiferromagnetism and ferromagnetism through the applied transverse electric field.It may be of great significance for the development of related magnetic-based nanodevices.In the end,it is found that the concentration and type have great influence on the properties of nanoribbons...