The structural properties,mechanical behavior,and electronic structure of the newly developed diamondlike BC5 (d-BC5) was investigated using density functional theory (DFT) calculations.The results indicate that d-BC5...The structural properties,mechanical behavior,and electronic structure of the newly developed diamondlike BC5 (d-BC5) was investigated using density functional theory (DFT) calculations.The results indicate that d-BC5 has great bulk modulus of 393 GPa,large shear modulus of 398 GPa,and high hardness of 62 Pa,and thus support the fact that d-BC5 is an ultra-incompressible and superhard material.Remarkably,the superhard d-BC5 exhibits metallic features.Furthermore,the trend that the mechanical behavior falls with the increase of boron content was revealed.The combination of huge stiffness,high hardness,and good metallicity makes series of diamondlike BCx (d-BCx) valid for wider applications in comparison with pure diamond.展开更多
Diamond like carbon films have been successfully deposited on the steel substrate, by using a single ion gun with varying beam source. The films may appear blue, yellow and transparent in color, which was found relate...Diamond like carbon films have been successfully deposited on the steel substrate, by using a single ion gun with varying beam source. The films may appear blue, yellow and transparent in color, which was found related to contaminants from the sample holder and could be avoided. The thickness of the films ranges from tens up to 200 nanometers, and the hardness is in the range 20 to 30 GPa. Raman analytical results reveal the films are in amorphous structure. The effects of different beam source on the films structure are further discussed.展开更多
基金Project supported by the National Natural Science Foundation of China (No.51072213)the Local Colleges Faculty Construction of Shanghai Municipal Science and Technology Commission (No.08210511900)and the Innovation Program of Shanghai Municipal Education Commission (No.11ZZ147),China
文摘The structural properties,mechanical behavior,and electronic structure of the newly developed diamondlike BC5 (d-BC5) was investigated using density functional theory (DFT) calculations.The results indicate that d-BC5 has great bulk modulus of 393 GPa,large shear modulus of 398 GPa,and high hardness of 62 Pa,and thus support the fact that d-BC5 is an ultra-incompressible and superhard material.Remarkably,the superhard d-BC5 exhibits metallic features.Furthermore,the trend that the mechanical behavior falls with the increase of boron content was revealed.The combination of huge stiffness,high hardness,and good metallicity makes series of diamondlike BCx (d-BCx) valid for wider applications in comparison with pure diamond.
文摘Diamond like carbon films have been successfully deposited on the steel substrate, by using a single ion gun with varying beam source. The films may appear blue, yellow and transparent in color, which was found related to contaminants from the sample holder and could be avoided. The thickness of the films ranges from tens up to 200 nanometers, and the hardness is in the range 20 to 30 GPa. Raman analytical results reveal the films are in amorphous structure. The effects of different beam source on the films structure are further discussed.
