Theoretical Study On Boundary Stability And Electromagnetic Properties Of Two-dimensional Materials

R esearchers found that graphene nanostructures with serrated edges showed obvious magnetic characteristics different from the two-dimensional counterparts due to the spin polarization of their edge states.T he quantum confinement effect makes the nanobelts have more unique functions and is expected to improve the efficiency of electronic devices.The electronic and magnetic properties of these low-dimensional systems have been widely studied in order to achieve great flexibility in the design and optimization of functional devices.T herefore,exploring the unique properties of new two-dimensional nanoribbons which are different from their two-dimensional counterparts has attracted attention.T his paper aims to explore the stability of the nanoribbon boundary of the new two-dimensional materials C r2B 2 and CrOCl and the different electromagnetic properties of these one-dimensional nanoribbons and their two-dimensional counterparts.Two-dimensional Cr2B2 is a member of transition metal boron compounds(M B ene)synthesized experimentally,and its electronic property is ferromagnetic metal.W e studied the structure,stability,electronic and magnetic properties of C r2B 2 nanoribbon.T he nanoribbons with only boron or chromium atoms on the edge structure are selected for calculation,and on this basis,atomic defects are produced on the edge structure.T he stability of the nanoribbon edge structure is evaluated by calculating the edge formation energy.Edge formation can indicate that the edge of nanoribbons is stable enough.We found that the edge formation energy of chromium nanoribbons is less than that of boron nanoribbons,indicating that they are more stable.D ue to the defects of the boundary boron atoms,some boron-atom-structured nanoribbons will open the band gap in the narrow band and become semiconductors.H owever,with the increase of nanoribbon width,their metal properties become stable.T he ground states of all the nanoribbons calculated at the chromium boundary are ferromagnetic metal,but the boundary structure shows an anti ferromagnetic coupling state.Two kinds of boundary nanoribbons from narrow to wide,the characteristics shown will provide a new platform for spintronic devices.Two-dimensional CrOC1 is a recently discovered material with high Tc.The twodimensional monolayer CrOCl is a ferromagnetic semiconductor and the predicted T c is up to 160 K,respectively.Its electronic property is ferromagnetic metal.W e calculated the stability and electromagnetic properties of six CrOC1 nanoribbons with different boundaries as the width increased.The stability of these nanobelts is determined by the calculated edge formation energy.A fter calculation we found that all the edge structures of nanoribbons are stable.T he edge formation energy of a kind of nanoribbons decreases with the increase of width,and the edge formation energy of a kind of nanoribbons increases with the increase of width.W hen the width is as low as one to three primitive cell widths,ferromagnetic semimetallic behavior occurs.A t the same time,when the boundary structure has defects,these nanobelts also maintain ferromagnetic semi-metallic behavior.A fter increasing the bandwidth,the nanobelts also maintain semi-metallicity,indicating that the conductivity of the twodimensional monolayer CrOCl nanoribbons has changed.In addition,we also calculated the transport properties of these nanoribbons,which were analyzed to be excellent electromagnetic conduction devices.