Shuming Zeng

Phonon-mediated superconductivity in borophenes

We use first-principles calculations to systematically investigate electronic, vibrational, and superconducting properties in borophenes (boron monolayer sheets). Remarkably, superconducting transition temperature Tc is a V-like function of hexagon hole density and has a similar tendency to the variations of the total energy and density of states at the Fermi level, which shows that the larger density of states at the Fermi level corresponds to the higher Tc. In consideration of substrate, the Ag(111) surfaces weaken the superconductivity in borophenes, which results in Tcμ*=0.1 of about 5.2 K in the buckled triangular sheet. As synthesis of borophenes was reported, superconducting boron sheets are feasible.

Magnetic properties of X-C2N (X=Cl, Br and I) monolayers: A first-principles study

The electronic and magnetic properties of X-C2N (X=F, Cl, Br and I) monolayers have been systematically investigated from first-principles calculations. The F atom can be strongly adsorbed on the top of the host carbon atoms, while the Cl, Br and I atoms favor the top of the host nitrogen atoms of C2N monolayers. These functionalized X-C2N (X=F, Cl, Br and I) monolayers exhibit interesting electronic and magnetic features. The F-C2N monolayer system shows a nonmagnetic metallic state, while the X-C2N (X=Cl, Br and I) monolayer systems exhibit the magnetic semiconducting ground state. Moreover, the ferromagnetic state is energetically more stable configuration for the X-C2N (X=Cl, Br and I) monolayer systems. Magnetic analysis further elaborates that the induced magnetism in the X-C2N (X=Cl, Br and I) monolayer systems mainly arises from the local magnetic moments of the halogen adatoms. Thus, the chemical functionalization of nitrogenated honey graphene through halogen atoms adsorption has promising applications in electronic devices.