The first-principle calculations and analysis on density of states of silion plane (111) formed by nitrogen film

The energy distribution of the interface states in the Si band-gap at an ultrathin oxide/Si(100) interface was investigated using a bias-voltage application in hard x-ray photoelectron spectroscopy. For the SiO2/Si interface, interface states were observed near the mid-gap, whereas the interface states for the SiON/Si interface increased around the mid-gap and new states formed near the conduction band minimum (CBM) and valence band maximum (VBM) compared to the case of the SiO2/Si interface. Moreover, the interface state density increased with the nitrogen concentration in the oxide, but the spectral shape was independent of the nitrogen concentration. The N1s spectra indicated that the N−O species at the SiON/Si interface induced inhomogeneous interface sites. Because inhomogeneity might break or weaken bonds at the SiON/Si interface, the density of broken bonds (the mid-gap states) and weakened bonds (the states near VBM and CBM) at the interface increased as the number of inhomogeneous sites increased.

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Experimental Study on Flexural Properties of Polyurethane–Cement Composites under Temperature Load

Liu

Jian

et al. 2022

Applied Sciences

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Polyurethane cement composite is a new organic–inorganic composite material with high strength, corrosion resistance, and fast curing. It is a complement and alternative to traditional cement materials. The flexural properties of polyurethane cement composites are the basic mechanical index of the material. In order to study the flexural properties under different temperature loads, a molecular model was established, the chemical reaction process of polyurethane cement and the temperature response mechanism was analyzed, and the preparation process of polyurethane cement was proposed. Then, bending tests were carried out in strain-controlled mode to obtain the specimens' bending strength and stiffness modulus under different temperature loads. The test results showed that the tensile strength of polyurethane cement decreased first, then increased, and finally decreased with the increase in temperature, while the bending stiffness modulus decreased with the increase in temperature. Combined with the theoretical derivation, the damage mode of the samples under different temperature loads was analyzed, and the “L-type” damage strain curve was obtained. The results showed that the proposed theory could effectively explain the mechanism of action and flexural properties of polyurethane cement composites under temperature loading, which is a significant improvement to the application of polyurethane cement composites in practical engineering.

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The first-principle calculations and analysis on density of states of silion plane (111) formed by nitrogen film

Cited by 3 publications

References 12 publications

HAXPES Applications to Advanced Materials

HAXPES Applications to Advanced Materials

Bias-voltage application in a hard x-ray photoelectron spectroscopic study of the interface states at oxide/Si(100) interfaces

Experimental Study on Flexural Properties of Polyurethane–Cement Composites under Temperature Load

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