Electronic structure and charge transfer in α- andβ−Si3N4and at the

Guang–Lin Zhao

¹

,

Martina E. Bachlechner

²

Abstract

Using a self-consistent linear combination of atomic orbitals method based on density-functional theory in a local-density approximation, the electronic structure in the high-temperature ceramics ␣-Si 3 N 4 and ␤-Si 3 N 4 and at the Si͑111͒/Si 3 N 4 ͑001͒ interface have been calculated. The resulting charge transfer suggests that the ionic formula can be written as Si 3 ϩ1.24 N 4 Ϫ0.93 . For the Si͑111͒/Si 3 N 4 ͑001͒ interface, the silicon atoms from the silicon side lose some electrons to the nitrogen atoms of the silicon nitride side forming Si-N bonds at the interface. The calculated electronic density of states spectrum of Si 2 p core levels for this interface is in good agreement with x-ray photoemission spectroscopy experiments. ͓S0163-1829͑98͒06928-8͔

Microscopic modeling of the dielectric properties of silicon nitride

“…In addition, recently there have been extensive studies of crystalline β-Si 3 N 4 thin films on Si, using either experimental 26 or theoretical techniques. 27,28 However investigations of dielectric properties have been extremely limited. Dielectric properties of amorphous thin film Si 3 N 4 have been studied in experiment, [29][30][31][32] and recently we have provided a theoretical analysis based on DFT.…”

Interface properties of Ge3N4/Ge(111): Ab initio and x-ray photoemission spectroscopy study

“…1͑a͒ is similar to an interface structure of ␤-Si 3 N 4 ͑0001͒ / Si͑111͒ proposed by Zhao and Bachlechner. 22 Three of the four Ge ͑smaller cyan atoms͒ atoms of the first Ge͑111͒ layer near the interface bond to three N atoms of ␤-Ge 3 N 4 , and the fourth Ge atom is right at the bottom of another N atom of ␤-Ge 3 N 4 . This structure has four dangling bonds at the interface per unit due to the unsaturated four Ge atoms ͓three Ge atoms ͑larger cyan atoms͒ from the first layer of Ge 3 N 4 at the interface and the other one from the first layer of Ge͑111͔͒.…”

Development of a high-efficiency high-resolution particle-induced x-ray emission system for chemical state analysis of environmental samples

“…We summarize the calculation results in Table II. The chemical shifts observed in our experiment and the effective charges given by other studies 17,20,21 are also listed in the table for comparison. The calculated chemical shift for SiC well reproduces the experimental value.…”