Search NASA⌕ Search

Engineering topics

Jinlong, Yang

Publications and source records attributed to Jinlong, Yang.

3 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Diamond as an inert substrate of graphene

Interaction between graphene and semiconducting diamond substrate has been examined with large-scale density functional theory calculations. Clean and hydrogenated diamond (100) and (111) surfaces have been studied. It turns out that weak van der Waals interactions dominate for graphene on all these surfaces. High carrier mobility of graphene is almost not affected, except for a negligible energy gap opening at the Dirac point. No charge transfer between graphene and diamond (100) surfaces is detected, while different charge-transfer complexes are formed between graphene and diamond (111) surfaces, inducing either p-type or n-type doping on graphene. Therefore, diamond can be used as an excellent substrate of graphene, which almost keeps its electronic structures at the same time providing the flexibility of charge doping.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2011

Prediction of formation of cubic boron nitride by construction of temperature-pressure phase diagram at the nanoscale

The size-dependent phase diagram of BN was developed on the basis of the nanothermodynamic theory. Our studied results suggest that cubic BN (c-BN) is more stable than hexagonal BN (h-BN) in the deep nanometer scale and the triple point of c-BN, h-BN and liquid shifts toward the lower temperature and pressure with decreasing the crystal size. Moreover, surface stress, which is determined by the experimental conditions, is the main reason to influence the formation of c-BN nuclei. The developed phase diagram of BN could help us to exploit new techniques for the fabrication of c-BN nanomaterials. - Graphical abstract: The size-dependent phase diagram of BN was developed on the basis of nanothermodynamic theory and it can be used to predict whether cubic BN (c-BN) can be formed at a given condition. Highlights: > Size-dependent phase diagram of BN is constructed. > Cubic BN is more stable than hexagonal BN in the deep nanometer scale. > Formation of nanosized cubic BN depends on surface stress.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗