Electronic and Magnetic Properties of Partially Open Carbon Nanotubes

Abstract

On the basis of the spin-polarized density functional theory calculations, we demonstrate that partially-open carbon nanotubes (CNTs) observed in recent experiments have rich electronic and magnetic properties which depend on the degree of the opening. A partially-open armchair CNT is converted from a metal to a semiconductor, and then to a spin-polarized semiconductor by increasing the length of the opening on the wall. Spin-polarized states become increasingly more stable than nonmagnetic states as the length of the opening is further increased. In addition, external electric fields or chemical modifications are usable to control the electronic and magnetic properties of the system. We show that half-metallicity may be achieved and the spin current may be controlled by external electric fields or by asymmetric functionalization of the edges of the opening. Our findings suggest that partially-open CNTs may offer unique opportunities for the future development of nanoscale electronics and spintronics. *

Ferromagnetic properties of single walled carbon nanotubes doped with manganese oxide using an electrochemical method

“…In this work, the Zener model description of carrier induced ferromagnetism 19,[23][24][25][26] with the transition metal doping in DMSs is not available in the SWCNTs because the effect of hole concentration on Curie temperature is not shown here due to the measurement limit of temperature. The enhanced ferromagnetic behavior of the Mn doped SWCNTs is mainly originated from the increase of manganese concentration though the possible formation of two-dimensional defect structures of SWCNTs with the 27 The Raman analysis of Figure 1(b) rules out this possibility from high quality SWCNTs. In addition, the enhanced ferromagnetic properties, remanent magnetization and the coercive field, with the increasing Mn concentration for the magnetic doping are observed in the magnetization versus magnetic field (M-H) curves of Figure 4 and the control of the ferromagnetic hysteresis is possible with the variation of manganese contents.…”

Three‐Terminal Graphene Nanoribbon Tunable Avalanche Transit Time Sources for Terahertz Power Generation

“…Various fabrication methodologies are now available in the literature for synthesizing high‐quality graphene‐based nanostructures. A number of techniques have been already developed for the nanoscale unzipping of graphene basal plane which is one of the cutting‐edge methods available for producing graphene nanoribbons (GNRs) . Moreover, one unique nanostructure, i.e., seamless interconnection between carbon nanotubes (CNTs) and GNRs, can be created by partial unzipping of CNTs .…”

Cascaded spintronic logic with low-dimensional carbon

“…This cascaded logic family creatively applies recent nanotechnological advances to efficiently achieve high-performance computing using only low-dimensional carbon materials161718192021222324. A spintronic switching device is proposed utilizing the negative magnetoresistance of graphene nanoribbon (GNR) transistors2526272829 and partially unzipped carbon nanotubes (CNTs)3031, unzipped3032333435 from metallic CNT interconnect.…”