B-N-C-O In 2-D

A hybrid of boron, nitrogen, carbon, and oxygen has joined the small but growing club of atomically thin two-dimensional materials (Sci. Adv. 2015, DOI: 10.1126/sciadv.1500094). The finding may lead to strategies for making other ultrathin multielement films with tunable properties for nanoelectronics. Previously, researchers had reported that two atomically thin materials, hexagonal boron nitride and graphene, could be hybridized via chemical vapor deposition (CVD) to form a distinct 2-D material, BNC. Swastik Kar and Birol Ozturk of Northeastern University and colleagues sought to understand how trace levels of oxygen invariably found in CVD instruments affect the BNC product. The team prepared a set of CVD films from methane and NH₃BH₃ while systematically admitting oxygen to the instrument at varying flow rates. They unexpectedly found a reproducible patchwork of micrometer sized BNCO domains in a BNC matrix. The domains’ sizes and compositions were tied to the O₂ concentration. Calculations predict that BNCO will be magnetic, possibly enabling applications in spintronics. This work constitutes a great leap in unlocking mysteries related to variations in electronic and magnetic properties of atomically thin 2-D materials,” says Saikat Talapatra, a thin-film physicist at Southern Illinois University, Carbondale.