It is demonstrated that sputtered thin film platinum ͑Pt͒ can be used as a catalytic metal for graphene growth on metal. During the crystallization annealing, the sputtered Pt is crystallized mostly into Pt ͑111͒ orientation, maintaining excellent surface roughness with no sign of agglomeration. The relatively lower carbon solubility in Pt and the good surface roughness of the thin film Pt enable us to form a uniform monolayer graphene on Pt over the entire region of the thin film Pt/ SiO 2 / Si substrate by carbon dissolution and segregation method processed in a methane ambient. The monolayer graphene grown on Pt has been successfully transferred to SiO 2 / Si substrate by simple wet etching of Pt. The results of Raman spectroscopic and scanning tunneling microscopic measurements of the synthesized graphene layer are presented.
This study reexamines the determinants of volatility spreads and suggests a new forecast of future volatilities. Contrary to earlier volatility forecasts, the newly introduced forecast is applicable when investors are not risk-neutral or when underlying returns do not follow a Gaussian probability distribution. This implies that the method is consistent with the presence of risk premia for other risks such as volatility risk. Using S&P 500 index options, we show that the new volatility forecast outperforms other volatility forecasts including risk-neutral implied volatility and historical volatility in two aspects. First, the new forecast is superior to other estimates in terms of forecasting errors for future realized volatilities. Second, it is an unbiased estimator of future realized volatilities. This is shown using an encompassing regression analysis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.